November 05, 2015

Targeting domains with Content Blockers

Surfin’ Safari

Content Blockers extensions are enjoying a tremendous success on iOS and Mac. Developers are being creative with the API and users love the speed and privacy benefits.

If you are interested in writing your own Content Blocker, I suggest starting with the introduction and the official documentation.

Content Blocker Extensions are different than traditional Safari extensions. Rather than have the engine (in this case, WebKit) ask extension code how to behave, the extension tells the engine how to behave in advance. Each Content Blocker extension defines a list of rules to follow, in order.

Each rule can be activated only when certain conditions are met. Those conditions are defined in the “trigger” of each rule. In this blog post, we are going to explore one particularly popular type of triggers: activation based on domain names.

Domain names and URL-filter

One of the most popular kind of trigger is activated based on matching certain domains. Typically, the author wants to prevent the browser from disclosing information to those domains.

The trigger specification does not have an explicit way of matching requests of a certain domain. Instead, the rule “url-filter” allow matching of a regular expression over the complete URL of every request.

There are many ways to write a regular expression that match a domain name. In general, the runtime performance is great regardless of how the expression is written.

What happens in the backend is that the Content Blocker engine compiles the rules into a small number of optimized finite state machines. Different ways of writing the same expression generates the same machines. Some definitions are more generic than others; it is the engine’s job to optimize them.

The bad news is different regular expressions can cause very different compile times. Some extensions compile in milliseconds while others compile in seconds. The more work we give to the optimizer, the longer the compilation process takes. On iOS, this translates into it taking longer after a user turns a content blocker on for it to apply to loaded pages.

In the following sections, we will see how the definition of URL-filters affects the compile time. The running example is to match “” and all its subdomains.

Generic domain matching

Before going through the Content Blocker engine, URLs are canonicalized.

The most direct way of matching a domain is to match the exact sequence of characters that can appear in a valid canonical URL. It would look something like this:

        "trigger": {
            "url-filter": "^[a-z][-+.0-9a-z]*:/+([!$%&'()*+,-.0-9:;=a-z_~]*@)?([-%0-9a-z_]+\\.)*a-tracker\\.com[:/]"
        "action": {
            "type": "block"

Compiling fifty thousand patterns of this form takes about 10 seconds in the worst case. A bit long.

The reason compiling such pattern takes a long time is its complexity. The optimizer has to spend a fair amount of time figuring the most efficient way to handle all the character sets.

Let’s simplify the expression for http-like URLs

The URL specifications give plenty of freedom on what can be defined. In most cases, we only care about the subset that matches URLs with the HTTP scheme.

We can improve the pattern by making the structure stricter!

First, the scheme and domain names are always lowercase in a canonical URL. We can change the trigger to:

    "trigger": {
        "url-filter": “^[a-z][-+.0-9a-z]*://+([!$%&'()*+,-.0-9:;=A-Za-z_~]*@)?([-%0-9a-z_]+\\.)*a-tracker\\.com[:/]”,

This is already 20% faster!

Next, let’s simplify the scheme definition.

When compiling “^[a-z][-+.0-9a-z]*://+“, the compiler generates code matching specifically the characters defined here. Matching the first character is easy, it just needs to be between “a” and “z” inclusive. Matching the next characters is a bit more complicated because more possibilities need to be tested.

There are two options to make that part trivial.

If it is okay to restrict the pattern to HTTP/HTTPS, using the pattern “^https?://+” is effective.

If you need to match any scheme, the pattern “^[^:]+://” is a good option. Instead of looking for a character in the range from “a” to “z”, the compiler can assume the input can be skipped until the first character “:”. This is a simpler operation, which makes it simpler to optimize.

We can use the same idea to match anything in front of the domain. Instead of matching the username, password and subdomains exactly, we can just exclude anything past the domain name.

We end up with a simplified expression like this:

    "trigger": {
        "url-filter": "^[^:]+://+([^:/]+\\.)?a-tracker\\.com[:/]",

Compiling fifty thousand patterns like this takes 2.7 seconds in the worst case, almost four times faster than the original pattern!


The Content Blocker compiler is there to optimize the performance of running Content Blockers. Such optimizations can take time.

If your extension has several thousand rules, it is worth looking into using simple regular expressions to reduce the compile time. Doing so ensures that users can enjoy the benefits of your extension as soon as it is activated.

For domain matching, my advice is to use triggers of the form:

    "trigger": {
        "url-filter": "^[^:]+://+([^:/]+\\.)?domain-to-match\\.tld[:/]",

For other cases, keep in mind the following:

  • Use “url-filter-is-case-sensitive” when possible. It halves the number of characters to consider.
  • Do not forget to escape special characters. In particular “.” can make a pattern much more generic than it needs to.
  • Sometimes, it is simpler to define what character should not match instead of listing everything that can match.

I would be happy to answer questions about anything related to Content Blockers in WebKit. You can find me on twitter at @awfulben. Brian can answer questions regarding the use of Content Blockers in Safari. As usual, you can also get in touch with Jon Davis with any other questions.

By Benjamin Poulain at November 05, 2015 02:00 PM

October 28, 2015

Carlos Alberto López Pérez: Introducing the meta-webkit Yocto layer.

Igalia WebKit

Lately, in my daily work at Igalia, I have been learning to use Yocto / OpenEmbedded to create custom distributions and products targeting different embedded hardware. One of the goals was to create a Kiosk-like browser that was based on a modern Web engine, light (specially regarding RAM requirements) and fast.

WebKit fits perfectly this requirements, so I started checking the available recipes on the different layers of Yocto to build WebKit, unfortunately the available recipes for WebKitGTK+ available were for ancient versions of the engine (no WebKit2 multi-process model). This has changed recently, as the WebKitGTK+ recipe available in the oe-core layer has been updated to a new version. In any case, we needed this for an older release of Yocto so I ended creating a new layer.

I have added also some recipes for WebKitForWayland and released it as meta-webkit. The idea is to collect here recipes for building browsers and web engines based on WebKit. For the moment it includes recipes for building the WebKitGTK+ and WebKitForWayland ports.

WebKitGTK+ vs WebKitForWayland

First a few words about the main differences between this two different ports of WebKit, so you have a better understanding on where to use one or the other.

Let’s start by defining both engines:

  • WebKit for Wayland port pairs the WebKit engine with the Wayland display protocol, allowing embedders to create simple and performant systems based on Web platform technologies. It is designed with hardware acceleration in mind, relying on EGL, the Wayland EGL platform, and OpenGL ES.
  • WebKitGTK+ is a full-featured port of the WebKit rendering engine, suitable for projects requiring any kind of web integration, from hybrid HTML/CSS applications to full-fledged web browsers. It offers WebKit’s full functionality and is useful in a wide range of systems from desktop computers to embedded systems like phones, tablets, and televisions.

From the definitions you may guess already some differences. WebKitForWayland focus on simple and performant Web-oriented systems, meanwhile WebKitGTK+ focus on any kind of product (complex or simple) that requires full Web integration.

WebKitForWayland is what you need when you want a very fast and light HTML5/js runtime, capable of squeeze the hardware acceleration of your platform (Wayland EGL platform) up to the maximum performance. But is not suitable if you are thinking in building a general purpose browser on top of it. It lacks some features that are not needed for a Web runtime but that are desirable for a more generic browser.

Here you can see a video of WebKitForWayland running on the weston ivi-shell and several instances of WebkitForWayland showing different demos (poster circle and several webgl demos) running on the Intel NUC (Intel Atom E3815 – 1 core). The OS is a custom image built with Yocto 1.8 and this meta-webkit layer.

On the Weston terminal you can appreciate the low resource usage (CPU and RAM) despite having several browser process running the demanding demos at full speed. Link to the video on YouTube here.

In case you want to try it, you might want to build an image for your device with meta-webkit and Yocto (see below), or you can test the image that I built for the demo on the above video. You can flash it to an usb stick memory device as follows, and boot it on any Intel x86_64 machine that has an Intel GPU:

# /dev/sdX is the device of your usb memory stick (for example /dev/sdc)
curl -s | xz -dc | dd bs=4k of=/dev/sdX

On the other hand WebKitGTK+ allows you to build a custom browser on top of it. It has a rich and stable API and many goodies like support for plugins, integrated web inspector, full toolkit support, etc. WebKitGTK+ also performs very good and consumes few resources, it can run both on top of Wayland and X11. But at the moment of writing this, the support for Wayland is still incomplete (we are working on it). So if possible we recommend that you base your product on the X11 backend. You could later migrate to Wayland without much effort once we complete the support for it.

Building a Yocto image with WebKitForWayland

The usual way to create an image with Yocto and WebKitForWayland is:

  • Setup the environment and source oe-init-build-env as usual.
  • Checkout the branch of meta-webkit that matches your Yocto/OE version (for example: fido).
    Note that fido (1.8) is the less recent version supported. If you are using the fido branch you will also need to add the meta-ruby layer that is available on meta-openembedded
  • Add the path to the meta-webkit layer in your conf/bblayers.conf file
  • Append the following lines to the conf/local.conf file
  • DISTRO_FEATURES_append = " opengl wayland"
    IMAGE_INSTALL_append = " webkitforwayland"
  • Then build the target image, for example
  • bitbake core-image-weston
  • Then boot the image on the target device and run the webkitforwayland engine from a weston terminal
  • WPELauncher

Building a Yocto image with WebKitGTK+

There are some things to take into account when building WebKitGTK+:

  • The package webkitgtk contains the shared libraries and the webkitgtk runtime.
  • The package webkitgtk-bin contains the MiniBrowser executable. This is very basic browser built on top of the webkitgtk runtime, mainly used for testing purposes.
  • On the recipe there are several packageconfig options that you can tune. For example, for enabling WebGL support you can add the following to your conf/local.conf file:
    PACKAGECONFIG_pn-webkitgtk = "x11 webgl"

    Check the recipe source code to see all the available options.

  • The name of the recipe is the same than the one available in oe-core (master), so you should select which version of webkitgtk you want to build. For example, to build 2.10.3 add on conf/local.conf:
    PREFERRED_VERSION_webkitgtk = "2.10.3"

So, the usual way to create an image with Yocto and WebKitGTK+ is:

  • Setup the environment and source oe-init-build-env as usual.
  • Checkout the branch of meta-webkit that matches your Yocto/OE version (for example: fido).
    Note that fido (1.8) is the less recent version supported. If you are using the fido branch you will also need to add the meta-ruby layer that is available on meta-openembedded
  • Add the following lines to your conf/local.conf file (for building the X11 backend of WebKitGTK+)
  • DISTRO_FEATURES_append = " opengl x11"
    IMAGE_INSTALL_append = " webkitgtk-bin"
  • Then build the X11 image:
  • bitbake core-image-sato
  • Then boot the image on the target device and run the included test browser from an X terminal (or any other browser that you have developed on top of the WebKitGTK+ API)
  • Further info

    If you are new to Yocto / OpenEmbedded, a good starting point is to check out the documentation.

    If you have any issue or doubt with the meta-webkit layer, please let me know about that (you can mail me at or open an issue on github)

    Finally, If you need help for integrating a Web engine on your product, you can also hire us. As maintainers of the GTK+ and WebKit For Wayland ports of WebKit we have considerable experience creating, maintaining and optimizing ports of WebKit.

    By clopez at October 28, 2015 01:23 PM

    October 26, 2015

    Introducing Shadow DOM API

    Surfin’ Safari

    We’re pleased to announce that basic support for the new slot-based shadow DOM API we proposed in April is now available in the nightly builds of WebKit after r190680.

    Shadow DOM is a part of Web Components, a set of specifications that were initially proposed by Google to enable the creation of reusable widgets and components on the Web. Shadow DOM, in particular, provides a lightweight encapsulation for DOM trees by allowing a creation of a parallel tree on an element called a “shadow tree” that replaces the rendering of the element without modifying the underlying DOM tree. Because a shadow tree is not an ordinary child of the “host” element to which it is attached, users of components cannot accidentally poke into it. Style rules are also scoped, meaning that CSS rules defined outside of a shadow tree do not apply to elements inside the shadow tree and rules defined inside the shadow tree do not apply to elements outside of it.

    Style Isolation

    One major benefit of using shadow DOM is style isolation. To see how, let’s say we want to create a custom progress bar. We can use two nested div’s to show the bar and another div with the text to show the percentage as follows:

    .progress { position: relative; border: solid 1px #000; padding: 1px; width: 100px; height: 1rem; }
    .progress > .bar { background: #9cf; height: 100%; }
    .progress > .label { position: absolute; top: 0; left: 0; width: 100%;
        text-align: center; font-size: 0.8rem; line-height: 1.1rem; }
    <template id="progress-bar-template">
        <div class="progress" role="progressbar" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100">
            <div class="bar"></div>
            <div class="label">0%</div>
    function createProgressBar() {
        var fragment = document.getElementById('progress-bar-template').content.cloneNode(true);
        var progressBar = fragment.querySelector('div');
        progressBar.updateProgress = function (newPercentage) {
            this.setAttribute('aria-valuenow', newPercentage);
            this.querySelector('.label').textContent = newPercentage + '%';
            this.querySelector('.bar').style.width = newPercentage + '%';
        return progressBar;

    Note the use of the template element, which allows authors to include a snippet of HTML that can be instantiated later by cloning the content. This was the first feature of Web Components we implemented in WebKit that later got merged into the HTML5 specification. A template element can appear anywhere in a document (e.g. between table and tr elements), and content inside template elements is inert and does not run scripts or load images and other types of subresources.

    Then the user of this custom progress bar can instantiate it and update the progress as follows:

    var progressBar = createProgressBar();

    The problem with this progress bar implementation is that its two internal divs are freely accessible to its users and its style rules are not scoped to the progress bar. For example, the style rules defined for the progress bar will apply to content outside the progress bar with the class name progress:

    <section class="project">
        <p class="progress">Pending an approval</p>

    Similarly, style rules defined for other elements could override rules in the progress bar:

    .label { font-weight: bold; }

    While we could work around these problems by using a custom element name such as custom-progressbar to scope rules and then initialize all other properties by all: initial, Shadow DOM provides a much more elegant solution.

    The idea here is to introduce an encapsulation layer at the outer div so that users of the progress bar don’t see its internals (such as divs created for the label and the bar) and styles defined for the progress bar don’t interfere with the rest of the page and vice versa.

    To do that, we first create a ShadowRoot on the progress bar by calling attachShadow({mode: 'closed'}), and then append various nodes needed for its implementation under it. Let’s say we’re still using a div to “host” this shadow root, then we can create a new div and attach a shadow root as follows:

    <template id="progress-bar-template">
            .progress { position: relative; border: solid 1px #000; padding: 1px; width: 100px; height: 1rem; }
            .progress > .bar { background: #9cf; height: 100%; }
            .progress > .label { position: absolute; top: 0; left: 0; width: 100%;
                text-align: center; font-size: 0.8rem; line-height: 1.1rem; }
        <div class="progress" role="progressbar" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100">
            <div class="bar"></div>
            <div class="label">0%</div>
    function createProgressBar() {
        var progressBar = document.createElement('div');
        var shadowRoot = progressBar.attachShadow({mode: 'closed'});
        progressBar.updateProgress = function (newPercentage) {
            shadowRoot.querySelector('.progress').setAttribute('aria-valuenow', newPercentage);
            shadowRoot.querySelector('.label').textContent = newPercentage + '%';
            shadowRoot.querySelector('.bar').style.width = newPercentage + '%';
        return progressBar;

    Notice that the style element is inside the template element and cloned into the shadow root along with the divs. This allows the style rules defined inside the shadow root to be scoped. Style rules defined outside a shadow root do not apply to elements inside the shadow root either.

    Tip: while debugging your code, you may find it helpful to use shadow DOM’s open mode so that you can access the newly created shadow root via the shadowRoot property of the host element. e.g. {mode: DEBUG ? 'open' : 'closed'}

    Composition with Slots

    At this point, you might be wondering why this had to be done in DOM instead of CSS. Styling is a presentational concept, so why should we add new elements to the DOM? In fact, the first public working draft of the CSS Scoping Module Level 1 defines the @scope rule, which enables exactly that. So why did we need to add another mechanism to isolate styles?

    One motivation was to allow elements used in the implementation of components to be hidden from node traversal APIs such as querySelectorAll and getElementsByTagName. Because nodes inside a shadow root are not found by these APIs by default, users of components that utilize shadow DOM do not need to worry about how each component is implemented. Each component is presented as an opaque element whose implementation details are encapsulated in its shadow DOM. Note that shadow DOM does not provide a cross-origin iframe-like security boundary. Scripts can easily bypass the shadow DOM boundary if needed.

    Another reason we need a DOM-based solution is for composition. Let’s say we have a list of contacts:

    <ul id="contacts">
            Commit Queue
            (<a href=""></a>)<br>
            One Infinite Loop, Cupertino, CA 95014
            Niwa, Ryosuke
            (<a href=""></a>)<br>
            Two Infinite Loop, Cupertino, CA 95014

    and we would like to add a fancy UI for each contact’s information in the list when scripts are enabled:

    Instead of copying all of this text over to our own shadow DOM, we can use named slots to render the text elsewhere in our shadow DOM without modifying the DOM as follows:

    <template id="contact-template">
            :host { border: solid 1px #ccc; border-radius: 0.5rem; padding: 0.5rem; margin: 0.5rem; }
            b { display: inline-block; width: 5rem; }
        <b>Name</b>: <slot name="fullName"><slot name="firstName"></slot> <slot name="lastName"></slot></slot><br>
        <b>Email</b>: <slot name="email">Unknown</slot><br>
        <b>Address</b>: <slot name="address">Unknown</slot>
    window.addEventListener('DOMContentLoaded', function () {
        var contacts = document.getElementById('contacts').children;
        var template = document.getElementById('contact-template').content;
        for (var i = 0; i < contacts.length; i++)
            contacts[i].attachShadow({mode: 'closed'}).appendChild(template.cloneNode(true));

    Conceptually, slots are holes in a shadow DOM that will be filled by children of its host element. Each element can be assigned into a slot of a specific name by the slot attribute as follows:

    <ul id="contacts">
            <span slot="fullName">Commit Queue</span>
            (<a slot="email" href=""></a>)<br>
            <span slot="address">One Infinite Loop, Cupertino, CA 95014</span>

    Here, we’re attaching a shadow root to the li, and each span with a slot attribute is assigned to the slot of the same name inside the shadow DOM. Let’s take a closer look at the shadow DOM template:

    <slot name="fullName">
        <slot name="firstName"></slot>
        <slot name="lastName"></slot>
    <b>Email</b>: <slot name="email">Unknown</slot><br>
    <b>Address</b>: <slot name="address">Unknown</slot>

    In this template, we have slots named fullName, which contains two other slots named firstName and lastName, and two additional slots named email and address. The fullName slot is taking the advantage of fallback content, and showing firstName and lastName only if there were no nodes assigned to the fullName slot. Even though there is exactly one node assigned to each slot in this example, multiple elements with the same slot attribute value can be assigned to a single slot, and they will appear in the order they appeared as the children of the host element. You can also use an unnamed default slot that will be filled by all of the host’s children that don’t have a slot attribute specified.

    When a Web browser renders this content, the content of the li element is replaced by the shadow DOM, and slots inside of it are replaced by their assigned node as if rendering the following DOM instead:

    <ul id="contacts">
                <slot name="fullName">
                        <span slot="fullName">Commit Queue</span>
                <slot name="email">
                        <a slot="email" href=""></a>
                <slot name="address">
                        <span slot="address">One Infinite Loop, Cupertino, CA 95014</span>

    As you can see, slot-based composition is a powerful tool that allows widgets to pull in the page content without cloning or modifying the DOM. With it, widgets can respond to changes made to its child nodes without MutationObservers or an explicit notification via script. In essence, composition turns the DOM into a communication medium between components.

    Styling the Host Element

    There is one more thing to note in the previous example, which had a mysterious pseudo-class :host:

    <template id="contact-template">
            :host { border: solid 1px #ccc; border-radius: 0.5rem; padding: 0.5rem; margin: 0.5rem; }
            b { display: inline-block; width: 5rem; }

    This pseudo class, as its name suggests, matches the host element of the shadow DOM in which this rule appears. By default, author style rules defined outside the shadow DOM have a higher precedence over rules defined in the shadow DOM. This allows a component to define its “default style”, and let users of the component override as needed.

    In addition, a component can use !important to force a certain style, such as width and display type, without which it cannot function properly with. Any !important rules defined inside a shadow DOM have a higher precedence over regular and !important rules defined outside the shadow DOM.

    Future Work

    There is still a lot of work left for Web Components. For styling, we would like to allow styling nodes assigned to a slot inside a shadow DOM. There is also a desire for components to respond to the document theme as well as exposing a stylable part to their users like CSS pseudo elements. In the longer term, we would like to see an imperative DOM API to manipulate slot assignments as we proposed a while ago.

    To complement shadow DOM, we’re also interested in custom elements. The custom elements API allows authors to associate a JavaScript class with a particular element name in HTML documents, and it’s a great way to attach shadow DOM and other custom behaviors idiomatically. Unfortunately, there are a few conflicting proposals on when and how to create a custom element. To help steer the discussion in W3C, we’re planning to prototype it in WebKit.

    For packaging and delivering Web Components, we’ve been working on ES6 modules. Like Mozilla, we believe modules will radically change the way authors strcuture their pages. We would also like to eventually design an API to create a fully isolated web component with an iframe-like security boundary on top of shadow DOM and custom elements.

    To conclude, we’re really excited about bringing a major feature of Web Components to WebKit, and we’ll keep you posted about more features coming your way. If you have any questions, please feel free to contact myself@WebKit, or Jon Davis.

    By Ryosuke Niwa at October 26, 2015 02:00 PM

    October 13, 2015

    ES6 in WebKit

    Surfin’ Safari

    ES6 brings a lot of new and interesting language features to JavaScript. ES6 has learned from many of JavaScript’s past mistakes and has crafted new language features that have clearer and easier to understand semantics. let and const are examples of this; they are block scoped declarations and thus not prone to the common errors caused by misunderstanding var scoping semantics. ES6 also includes features that are designed to make common JavaScript idioms feel more natural. As an example, arrow functions make it easy to write small functions that have a lexically bound this; something JavaScript programmers do quite often. class syntax makes it easier to write classical object oriented code that is commonplace in many programs. Destructuring syntax helps remove boiler plate that is found in any sufficiently large JavaScript program.

    We on the WebKit team are really excited about ES6 and have been working hard on implementing it. In Safari 9 for El Capitan and iOS 9 you’ll be able to use some great ES6 features:

    There are even more ES6 features you can try out if you run the latest WebKit nightly build. We’ve recently implemented:

    If you’re interested in following our ES6 implementation and trying out ES6, download a WebKit nightly build. You can also help us fix any bugs in our current implementation by reporting any bugs you find. Also, if you (yes, you, the reader) are interested in adding any ES6 features to WebKit or even just fixing a few bugs, I’d be more than happy to help you get started. You can get in touch with me on twitter: @saambarati. And as always, you can get in touch with @jonathandavis with any other questions

    By Saam Barati at October 13, 2015 02:00 PM

    October 06, 2015

    Manuel Rego: Grid Layout Coast to Coast

    Igalia WebKit

    So here we’re again, this time to announce that I’ll be presenting my talk CSS Grid Layout from the inside out at HTML5DevConf Autumn 2015 (19-20 October). I’m really excited about this new opportunity to show the world the wonders of CSS Grid Layout specification, together with the “dark” stuff that happens behind the scenes. Thanks to the organization for counting me in. 😃

    My talk announced at the HTML5DevConf website My talk announced at the HTML5DevConf website

    During the talk I’ll give a short introduction to the grid layout syntax and features, including some of the most recent developments, like the much awaited grid gutters (which will hopefully land very soon). Igalia has been working on the CSS Grid Layout implementation on Blink and WebKit since 2013 as part of a collaboration with Bloomberg. Right now we’re closer than ever to ship the feature in Chromium!

    Igalia and Bloomberg working together to build a better web Igalia and Bloomberg working together to build a better web

    This’ll be my second grid layout talk this year after the one at CSSConf in New York. It’ll be my first time at HTML5DevConf and my first time in San Francisco too. It seems a huge conference full of great speakers and interesting talks. I really hope that people like my talk, anyway I’m sure I’ll enjoy the conference and learn a lot about the latest cool stuff that is moving around the web platform. Please, feel free to ping me if you want to talk about grid, new layout models, the web and/or Igalia.

    Last but not least, my igalian mate Martin Robinson who is currently hacking on Servo will be attending the conference too. Don’t hesitate to ask him any question about web browser engines, he knows them very well. 😉

    October 06, 2015 10:00 PM

    Web Inspector Keyboard Shortcuts

    Surfin’ Safari

    Web Inspector is loaded with tools to make web development easier and more effective. To help you become more efficient, Web Inspector includes keyboard shortcuts for many commonly used actions. These shortcuts will help you streamline your interactions and reduce the effort needed to complete your work.

    Keyboard Shortcuts

    You can learn about the shortcuts by hovering over interface elements and examining their tooltips. We’ve compiled a handy reference list of useful shortcuts to make working with Web Inspector more effortless.

    Debugger Shortcuts

    Debugger Shortcuts

    ⌘Y Disable breakpoints
    ⌃⌘Y or ⌘\ Continue script execution
    F6 or ⌘’ Step over
    F7 or ⌘; Step in
    F8 or ⇧⌘; Step out

    These shortcuts work from any Web Inspector panel, not just Debugger. One exception is ⌘Y — when editing code, ⌘Y comments out a line.



    ⌘⇧F — global search, it searches in all resources.
    ⌘F — local search, search within currently selected panel (e.g. a resource or console).

    CSS selectors and XPath can be used for both global and local search.

    Hide an Element

    The H key hides the currently selected element by assigning “visibility: hidden” to it. Unlike deleting a node (by pressing delete key or setting “display: none”), setting “visibility: hidden” doesn’t move any other elements on the web page.

    Select Next and Previous Tabs

    Much like ⌘⇧] and ⌘⇧[ select next and previous tabs respectively in Safari, ⌘⇧] and ⌘⇧[ select next and previous tabs in WebKit Inspector when it’s undocked.

    Toggle Split Console

    The Esc key focuses on the quick console. Once it’s focused, pressing Esc toggles the split console.

    Console Filters

    Several filters can be selected by clicking while holding key.

    Clear console

    Clear console

    Console can be cleared not only by clicking on the trash icon or by executing console.clear(), but also by pressing ⌘K or ⌃L.


    All these keyboard shortcuts are available in both Safari 8 and 9. Please message @webkit on Twitter about keyboard shortcuts you like, don’t like or want to be implemented. If it doesn’t fit into 140 characters, file a bug report.

    By Nikita Vasilyev at October 06, 2015 02:00 PM

    September 23, 2015

    Xabier Rodríguez Calvar: WebKit Contributors Meeting 2015 (late, I know)

    Igalia WebKit

    After writing my last post I realized that I needed to write a bit more about what I had been doing at the WebKit Contributors Meeting.

    First thing to say is that it happened in March at Apple campus in Cupertino and I atteded as part of the Igalia gang.

    My goal when I went there was to discuss with Youenn Fablet about Streams API and we are implementing and see how we could bootstrap the reviews and being to get the code reviewed and landed efficiently. Youenn and I also made a presentation (mainly him) about it. At that moment we got some comments and help from Benjamin Poulain and nowadays we are also working with Darin Adler and Geoffrey Garen so the work is ongoing.

    WebRTC was also a hot topic and we talked a bit about how to deal with the promises as they seem to be involved in the WebRTC standard was well. My Igalian partner Philippe was missed in this regard as he is involved in the development of WebRTC in WebKit, but he unfortunately couldn’t make it because of personal reasons.

    I also had an interesting talk with Jer Noble and Eric Carlson about Media Source and Encrypted Media Extensions. I told them about the several downstream implementations that we are or were working on, specially the WebKit4Wayland one and that we expect to begin to upstream soon. They commented that they still have doubts about the abstractions they made for them and of course I promised to get back to them when we begin with the job. Actually I already discussed some issues with Quique, another fellow Igalian.

    Among the other interesting discussions, I found very necessary the migration of Mac port to CMake. Actually, I am experiencing now the painbenefits of using XCode to add files, specially the generated ones to the compilation. I hope that Alex succeeds with the task and soon we have a common build system for all main ports.

    By calvaris at September 23, 2015 04:36 PM

    September 21, 2015

    Carlos García Campos: WebKitGTK+ 2.10

    Igalia WebKit

    HTTP Disk Cache

    WebKitGTK+ already had an HTTP disk cache implementation, simply using SoupCache, but Apple introduced a new cross-platform implementation to WebKit (just a few bits needed a platform specific implementation), so we decided to switch to it. This new cache has a lot of advantages over the SoupCache approach:

    • It’s fully integrated in the WebKit loading process, sharing some logic with the memory cache too.
    • It’s more efficient in terms of speed (the cache is in the NetworkProcess, but only the file descriptor is sent to the Web Process that mmaps the file) and disk usage (resource body and headers are stored in separate files in disk, using hard links for the body so that difference resources with the exactly same contents are only stored once).
    • It’s also more robust thanks to the lack of index. The synchronization between the index and the actual contents has always been a headache in SoupCache, with many resources leaked in disk, resources that are cache twice, etc.

    The new disk cache is only used by the Network Process, so in case of using the shared secondary process model the SoupCache will still be used in the Web Process.

    New inspector UI

    The Web Inspector UI has been redesigned, you can see some of the differences in this screenshot:


    For more details see this post in the Safari blog


    This was one the few regressions we still had compared to WebKit1. When we switched to WebKit2 we lost IndexedDB support, but It’s now back in 2.10. It uses its own new process, the DatabaseProcess, to perform all database operations.


    WebKitGTK+ 2.8 improved the overall performance thanks to the use of the bmalloc memory allocator. In 2.10 the overall performance has also improved, this time thanks to a new implementation of the locking primitives. All uses of mutex/condition have been replaced by a new implementation. You can see more details in the email Filip sent to webkit-dev or in the so detailed commit messages.

    Screen Saver inhibitor

    It’s more and more common to use the web browser to watch large videos in fullscreen mode, and quite annoying when the screen saver decides to “save” your screen every x minutes during the whole video. WebKitGTK+ 2.10 uses the ScreenSaver DBus service to inhibit the screen saver while a video is playing in fullscreen mode.

    Font matching for strong aliases

    WebKit’s font matching algorithm has improved, and now allows replacing fonts with metric-compatible equivalents. For example, sites that specify Arial will now get Liberation Sans, rather than your system’s default sans font (usually DejaVu). This makes text appear better on many pages, since some fonts require more space than others. The new algorithm is based on code from Skia that we expect will be used by Chrome in the future.

    Improve image quality when using newer versions of cairo/pixman

    The poor downscaling quality of cairo/pixman is a well known issue that was finally fixed in Cairo 1.14, however we were not taking advantage of it in WebKit even when using a recent enough version of cairo. The reason is that we were using CAIRO_FILTER_BILINEAR filter that was not affected by the cairo changes. So, we just switched to use CAIRO_FILTER_GOOD, that will use the BILINEAR filter in previous versions of Cairo (keeping the backwards compatibility), and a box filter for downscaling in newer versions. This drastically improves the image quality of downscaled images with a minim impact in performance.

    New API

    Editor API

    The lack of editor capabilities from the API point of view was blocking the migration to WebKit2 for some applications like Evolution. In 2.10 we have started to add the required API to ensure not only that the migration is possible for any application using a WebView in editable mode, but also that it will be more convenient to use.

    So, for example, to monitor the state of the editor associated to a WebView, 2.10 provides a new class WebKitEditorState, that for now allows to monitor the typing attributestyping attributes. With WebKit1 you had to connect to the selection-changed signal and use the DOM bindings API to manually query the typing attributes. This is quite useful for updating the state of the editing buttons in the editor toolbar, for example. You just need to connect to WebKitEditorState::notify::typying-attributes and update the UI accordingly. For now typing attributes is the only thing you can monitor from the UI process API, but we will add more information when needed like the current cursor position, for example.

    Having WebKitEditorState doesn’t mean we don’t need a selection-changed signal that we can monitor to query the DOM ourselves. But since in WebKit2 the DOM lives in the Web Process, the selection-changed signal has been added to the Web Extensions API. A new class WebKitWebEditor has been added, to represent the web editor associated to a WebKitWebPage, and can be obtained with webkit_web_page_get_editor(). And is this new class the one providing the selection-changed signal. So, you can connect to the signal and use the DOM API the same way it was done in WebKit1.

    Some of the editor commands require an argument, like for example, the command to insert an image requires the image source URL. But both the WebKit1 and WebKit2 APIs only provided methods to run editor commands without any argument. This means that, once again, to implement something like insert-image or insert link, you had to use the DOM bindings to create and insert the new elements in the correct place. WebKitGTK+ 2.10 provides webkit_web_view_execute_editing_command_with_argument() to make this a lot more convenient.

    You can test all this features using the new editor mode of MiniBrowser, simply run it with -e command line option and no arguments.


    Website data

    When browsing the web, websites are allowed to store data at the client side. It could be a cache, like the HTTP disk cache, or data required by web features like offline applications, local storage, IndexedDB, WebSQL, etc. All that data is currently stored in different directories and not all of those could be configured by the user. The new WebKitWebsiteDataManager class in 2.10 allows you to configure all those directories, either using a common base cache/data directory or providing a specific directory for every kind of data stored. It’s not mandatory to use it though, the default values are compatible with the ones previously used.

    This gives the user more control over the browsing data stored in the client side, but in the future versions we plan to add support for actually handling the data, so that you will be able to query and delete the data stored by a particular security domain.

    Web Processes limit

    WebKitGTK+ currently supports two process models, the single shared secondary process and the multiple secondary processes. When using the latter, a new web process is created for every new web view. When there are a lot of web views created at the same time, the resources required to create all those processes could be too much in some systems. To improve that a bit 2.10 adds webkit_web_context_set_web_process_count_limit(), to set the maximum number of web process that can be created a the same time.

    This new API can also be used to implement a slightly different version of the shared single process model. By using the multiple secondary process model with a limit of 1 web process, you still have a single shared web process, but using the multi-process mechanism, which means the network will happen in the Network Process, among other things. So, if you use the shared secondary process model in your application, unless your application only loads local resources, we recommend you to switch to multiple process model and use the limit to benefit from all the Network Process feature like the new disk cache, for example. Epiphany already does this for the secondary process model and web apps.

    Missing media plugins installation permission request

    When you try to play media, and the media backend doesn’t find the plugins/codecs required to play it, the missing plugin installation mechanism starts the package installer to allow the user to find and install the required plugins/codecs. This used to happen in the Web Process and without any way for the user to avoid it. WebKitGTK+ 2.10 provides a new WebKitPermissionRequest implementation that allows the user to block the request and prevent the installer from being invoked.

    By carlos garcia campos at September 21, 2015 11:52 AM

    September 15, 2015

    Scroll Snapping with CSS Snap Points

    Surfin’ Safari

    Many of you, as web developers, are trying to accomplish sophisticated scrolling effects such as paginated scrolling. WebKit now supports paginated scrolling through CSS Snap Points. Though some JavaScript scrolling libraries already allow you to implement paginated scrolling on your websites and web views, these approaches have important weaknesses – first, they run JavaScript on every frame of a scrolling animation, which WebKit’s fast scrolling infrastructure cannot optimize. Second, the current event model standard does not expose trackpad scrolling phases, making it difficult for you to get optimal paged scrolling using JavaScript. Fortunately, with scroll snapping, you won’t need information about scrolling phases to implement great paginated scrolling.

    New CSS Properties

    Scroll snapping allows you to define special points in the content of a scrollable container using CSS. When a user scrolls in this container, the scroll offset will come to rest at one of these special offsets. To motivate snap scrolling, consider this horizontally scrolling gallery:

    Notice how scrolling can leave us at an awkward position where we see a sliver of one image and only part of the next. Let’s look at how we can use the new scroll-snap-* properties to achieve paginated scrolling. Note that the examples shown in this post are all available in this scroll snapping gallery.

    Scroll Snap Type

    By default, scroll-snap-type on the parent scrolling container is none, which indicates that the container opts out of any scroll snapping behavior. To opt in, we set the value to be mandatory, which guarantees that the visual viewport of the container will rest on a snap point when there are no active scrolling operations. Also note that another value for scroll-snap-type is proximity, which indicates that scrolling may come to rest on a snap point only if scrolling takes us near the snap point. Currently, WebKit only supports mandatory snapping.

    Scroll Snap Points-X and -Y

    The scroll-snap-points-x and scroll-snap-points-y properties determine how to place snap points along the horizontal and vertical axes of the scroll snap container, respectively. The values here are none (the default) or repeat(<length>), where a CSS <length> unit indicates any type of expression indicating a length. These include raw pixel values, viewport units, percentages (relative to the container’s padding box) and even calc() expressions. Please note that negative repeat() values are handled as parsing errors, and any value that comes out to less than 1px is clamped to 1px. A repeat() value indicates that snap points should be placed at regular intervals along the x or y axes, respectively. Using the above two properties, here is an example of mandatory scroll snapping with horizontal snap points at every 100% of the container width using repeat(100%). If you’re on a browser that supports scroll snapping, you can also check out Scroll Snapping Demo 1.

    Each snap point is located at the top left corner of each image. Scroll snapping makes each snap point come to rest at the top left corner of the container, marked by the blue cross.

    Scroll Snap Coordinate

    If our images are different sizes, we won’t be able to use repeat(), since the interval will vary from image to image. Instead, we can use scroll-snap-coordinate on a child element to generate one or more snap points relative to each child element. This property accepts either “none” or a space-separated list of coordinates. Each coordinate is of the form <length> <length>, representing the x and y positions of the coordinate, respectively. Just like before, each <length> is generalized to match any generic length value, and percentage-based length values use the dimensions of the child element’s border-box. The following example places a snap coordinate at each child element’s top left corner, allowing us to snap to unevenly spaced elements. See Scroll Snapping Demo 2.

    Scroll Snap Destination

    Another way to improve the gallery would be to center each image relative to the container. Up until now, we’ve been aligning each snap point to the top left corner of the parent container. However, by changing scroll-snap-destination, we’re able to manipulate where snap points animate to. The destination value is a single position consisting of two space-separated <length>s. Percentage-based values are computed relative to the padding box of the scroll snapping container. We use this property in conjunction with scroll-snap-coordinate on each child element to animate each child element to the center of the container. See Scroll Snapping Demo 3.

    Notice that the position of the blue cross is now in the center of the container, since we set the destination to 50% 50%. The snap points are also now in the center of each child element, so the center of each child element now comes to rest at the center of the container.

    Additional Details

    Our scroll snapping implementation supports 2D snapping as well, when scroll snap points in both axes are active or when elements are positioned in a grid-like fashion in a container. Scrolling diagonally animates the scroll offset on a curved path to its destination. See Scroll Snapping Demo 4.

    We also support scroll snapping on containers to which CSS transformations have been applied. See Scroll Snapping Demo 5.

    Standards Compliance and Future Work

    We currently only support the most complete part of the snap points specification: 2D scroll snapping to child elements that are aligned on a grid. This means you may find more snap points than expected if your 2D scrolling container contains scroll snapping elements of uneven sizes, such as in a masonry grid layout.

    The CSS Scroll Snap Points specification is still a work in progress. We are considering the CSS Scroll Snapping Change Proposal. Once a consensus is reached we will either implement the alternative scrolling model, or implement the proximity type for scroll snapping, tracked by bug 135994.

    Since the specification is still in flux, we have prefixed our implementation with -webkit in keeping with the W3C requirements for features that have not completed the standardization process. We intend to unprefix our scroll snapping properties once the specification approaches its final state.

    The spec also does not explicitly state how to handle unreachable snap points. Our current implementation clamps all x and y offsets of each snap point to the min and max scroll offsets of the scroll snapping container. Furthermore, to prevent content from being unreachable, we emit snap points at the min and max scroll offsets of the container as well.

    You can use scroll snapping on the nightlies, as well as Safari on OS X El Capitan and iOS 9. We hope you’ve enjoyed reading about scroll snapping, and we’re excited to see what you create with it!

    By Wenson Hsieh at September 15, 2015 02:00 PM

    September 08, 2015

    Introducing the Rendering Frames Timeline

    Surfin’ Safari

    Being able to measure performance and identify bottlenecks is essential for web developers of modern web applications. Delivering a smooth user experience can be a challenge as complex scripts, dependencies on third-party JavaScript frameworks, and high performance animations become the norm. Most of today’s devices have displays which refresh at 60 Hz, which means our apps need to update at a consistent 60 frames per second.

    Web Inspector includes a new tool to help locate and resolve rendering performance issues. In addition to the familiar event-based timelines, the Timelines tab now includes a Rendering Frames mode, a new timeline presenting a frame-based, task-specific view of existing profiler/instrumentation data.

    Web Inspector Rendering Frames Timeline

    The Event Loop

    Each frame in the timeline represents a single cycle of the browser’s event processing loop, broken down into the tasks that executed during that time. During a single cycle of the event loop, the browser must:

    1. Handle events and timers
    2. Run JavaScript
    3. Perform style calculations and layout
    4. Paint and composite the page

    If one or more of these tasks takes an excessive amount of time, frame rates can drop and page performance can suffer. To maintain a consistent 60 FPS frame rate, the time budget for each frame is about 16.667 ms, or 1 / 60 of a second.


    Frame data is displayed in three panels: an overview graphrecords table, and summary chart. The graph panel (at the top of the view) shows a high-level overview of rendering times and long-running tasks. The records table (bottom half) shows details about what happened in every single frame, and the summary chart gives the aggregate time for the frame records currently selected in the timeline.

    The Rendering Frames timeline plots discrete frames along the x-axis; each frame’s height corresponds to how long it took to render (lower is better). This is in contrast to other timelines in the Web Inspector, which plot events over time on the x-axis and don’t have a y-axis.

    Rendering Frames Overview Graph

    When there’s no script activity or layout changes to render, WebKit’s event loop remains idle. By default, the Rendering Frames timeline automatically hides these idle periods so you can easily compare periods of activity.

    The above example shows a profile taken from a page that performed some work once per second with a call to setInterval. According to the Start Time column, each frame is about one second apart, and the interval between frames – idle time – is not shown.

    Identifying Performance Problems

    When web content has poor rendering performance, this shows up as tall bars in the timeline or frames with large values in the Total Time table column. Filters, which are discussed in the next section, can also aid in highlighting just those frames which consistently fail to meet our 60 FPS goal. The next step is determining what script or layouts are eating up our frame budget:

    Filtering Data

    When rendering up to 60 frames per second, complex web content can quickly generate large recordings that obscure infrequent, but annoying, frame drops. The Rendering Frames timeline adds two new filter types to help reduce the noise: a task filter and frame duration filter. Both filter options are located in the Timelines sidebar panel.

    As with all timeline views, only the range of data selected in the timeline overview graph is shown in the records table.

    Frame Filtering Options

    All selected frames are shown in the overview graph and data grid by default. In the example below, this includes many frames well within the ~16 ms budget, and quite a few that are little more than a blip on the graph:

    Unfiltered Frame Data

    Duration filters are useful for hiding frames that don’t take a significant time to render. Below is the same data after filtering out frames which took less than 15 ms to render:

    Filtered Frame Data

    Filtered frames are de-emphasized in the overview graph, and hidden in the timeline records table. Applying filters reduces the amount of profile data which must be investigated. Data can be filtered even further by applying task filters:

    Frame Task Filters

    Final Thoughts

    Knowing how your site spends its time is crucial for delivering smoothly rendered content and a snappy user experience. The Rendering Frames timeline is a great tool for identifying performance issues, and this is just the beginning. There are many enhancements and features planned for this and other areas of the Web Inspector, and we’re interested in hearing your feedback.

    The Rendering Frames timeline is available to use in the Safari 9 beta, and the latest features and enhancements can be found in WebKit Nightly Builds. Help us make Web Inspector even better by sending us feedback on Twitter (@xeenon, @jonathandavis, @matt_a_baker), or by filing a bug.

    By Matt Baker at September 08, 2015 02:00 PM

    July 25, 2015

    Michael Catanzaro: Useful DuckDuckGo bangs

    Igalia WebKit

    DuckDuckGo bangs are just shortcuts to redirect your search to another search engine. My personal favorites:

    • !gnomebugs — Runs a search on GNOME Bugzilla. Especially useful followed by a bug number. For example, search for ‘!gnomebugs 100000’ and see what you get.
    • !wkb — Same thing for WebKit Bugzilla.
    • !w — Searches Wikipedia.

    There’s 6388 more, but those are the three I can remember. If you work on GNOME or WebKit, these are super convenient.

    By Michael Catanzaro at July 25, 2015 01:47 AM

    July 23, 2015

    Xabier Rodríguez Calvar: ReadableStream almost ready

    Igalia WebKit

    Hello dear readers! Long time no see! You might thing that I have been lazy, and I was in blog posting but I was coding like mad.

    First remarkable thing is that I attended the WebKit Contributors Meeting that happened in March at Apple campus in Cupertino as part of the Igalia gang. There we discussed of course about Streams API, its state and different implementation possibilities. Another very interesting point which would make me very happy would be the movement of Mac to CMake.

    In a previous post I already introduced the concepts of the Streams API and some of its possible use cases so I’ll save you that part now. The news is that ReadableStream has its basic funcionality complete. And what does it mean? It means that you can create a ReadableStream by providing the constructor with the underlying source and the strategy objects and read from it with its reader and all the internal mechanisms of backpresure and so on will work according to the spec. Yay!

    Nevertheless, there’s still quite some work to do to complete the implementation of Streams API, like the implementation of byte streams, writable and transform streams, piping operations and built-in strategies (which is what I am on right now).I don’t know either when Streams API will be activated by default in the next builds of Safari, WebKitGTK+ or WebKit for Wayland, but we’ll make it at some point!

    Code suffered already lots of changes because we were still figuring out which architecture was the best and Youenn did an awesome job in refactoring some things and providing support for promises in the bindings to make the implementation of ReadableStream more straitghforward and less “custom”.

    Implementation could still suffer quite some important changes as, as part of my work implementing the strategies, some reviewers raised their concerns of having Streams API implemented inside WebCore in terms of IDL interfaces. I have already a proof of concept of CountQueuingStrategy and ByteLengthQueuingStrategy implemented inside JavaScriptCore, even a case where we use built-in JavaScript functions, which might help to keep closer to the spec if we can just include JavaScript code directly. We’ll see how we end up!

    Last and not least I would like to thank Igalia for sponsoring me to attend the WebKit Contributors Meeting in Cupertino and also Adenilson for being so nice and taking us to very nice places for dinner and drinks that we wouldn’t be able to find ourselves (I owe you, promise to return the favor at the Web Engines Hackfest). It was also really nice to have the oportunity of quickly visiting New York City for some hours because of the long connection there which usually would be a PITA, but it was very enjoyable this time.

    By calvaris at July 23, 2015 04:17 PM

    December 15, 2014

    Web Engines Hackfest 2014

    Gustavo Noronha

    For the 6th year in a row, Igalia has organized a hackfest focused on web engines. The 5 years before this one were actually focused on the GTK+ port of WebKit, but the number of web engines that matter to us as Free Software developers and consultancies has grown, and so has the scope of the hackfest.

    It was a very productive and exciting event. It has already been covered by Manuel RegoPhilippe Normand, Sebastian Dröge and Andy Wingo! I am sure more blog posts will pop up. We had Martin Robinson telling us about the new Servo engine that Mozilla has been developing as a proof of concept for both Rust as a language for building big, complex products and for doing layout in parallel. Andy gave us a very good summary of where JS engines are in terms of performance and features. We had talks about CSS grid layouts, TyGL – a GL-powered implementation of the 2D painting backend in WebKit, the new Wayland port, announced by Zan Dobersek, and a lot more.

    With help from my colleague ChangSeok OH, I presented a description of how a team at Collabora led by Marco Barisione made the combination of WebKitGTK+ and GNOME’s web browser a pretty good experience for the Raspberry Pi. It took a not so small amount of both pragmatic limitations and hacks to get to a multi-tab browser that can play youtube videos and be quite responsive, but we were very happy with how well WebKitGTK+ worked as a base for that.

    One of my main goals for the hackfest was to help drive features that were lingering in the bug tracker for WebKitGTK+. I picked up a patch that had gone through a number of iterations and rewrites: the HTML5 notifications support, and with help from Carlos Garcia, managed to finish it and land it at the last day of the hackfest! It provides new signals that can be used to authorize notifications, show and close them.

    To make notifications work in the best case scenario, the only thing that the API user needs to do is handle the permission request, since we provide a default implementation for the show and close signals that uses libnotify if it is available when building WebKitGTK+. Originally our intention was to use GNotification for the default implementation of those signals in WebKitGTK+, but it turned out to be a pain to use for our purposes.

    GNotification is tied to GApplication. This allows for some interesting features, like notifications being persistent and able to reactivate the application, but those make no sense in our current use case, although that may change once service workers become a thing. It can also be a bit problematic given we are a library and thus have no GApplication of our own. That was easily overcome by using the default GApplication of the process for notifications, though.

    The show stopper for us using GNotification was the way GNOME Shell currently deals with notifications sent using this mechanism. It will look for a .desktop file named after the application ID used to initialize the GApplication instance and reject the notification if it cannot find that. Besides making this a pain to test – our test browser would need a .desktop file to be installed, that would not work for our main API user! The application ID used for all Web instances is org.gnome.Epiphany at the moment, and that is not the same as any of the desktop files used either by the main browser or by the web apps created with it.

    For the future we will probably move Epiphany towards this new era, and all users of the WebKitGTK+ API as well, but the strictness of GNOME Shell would hurt the usefulness of our default implementation right now, so we decided to stick to libnotify for the time being.

    Other than that, I managed to review a bunch of patches during the hackfest, and took part in many interesting discussions regarding the next steps for GNOME Web and the GTK+ and Wayland ports of WebKit, such as the potential introduction of a threaded compositor, which is pretty exciting. We also tried to have Bastien Nocera as a guest participant for one of our sessions, but it turns out that requires more than a notebook on top of a bench hooked up to   a TV to work well. We could think of something next time ;D.

    I’d like to thank Igalia for organizing and sponsoring the event, Collabora for sponsoring and sending ChangSeok and myself over to Spain from far away Brazil and South Korea, and Adobe for also sponsoring the event! Hope to see you all next year!

    Web Engines Hackfest 2014 sponsors: Adobe, Collabora and Igalia

    Web Engines Hackfest 2014 sponsors: Adobe, Collabora and Igalia

    By kov at December 15, 2014 11:20 PM

    December 08, 2014

    How to build TyGL

    University of Szeged

    This is a follow-up blog post of our announcement of TyGL - the 2D-accelerated GPU rendering port of WebKit.

    We have been received lots of feedback about TyGL and we would like to thank you for all questions, suggestions and comments. As we promised lets get into some technical details.

    read more

    By szilard.ledan at December 08, 2014 12:47 PM

    November 12, 2014

    Announcing the TyGL-WebKit port to accelerate 2D web rendering with GPU

    University of Szeged

    We are proud to announce the TyGL port (link: on the top of EFL-WebKit. TyGL (pronounced as tigel) is part of WebKit and provides 2D-accelerated GPU rendering on embedded systems. The engine is purely GPU based. It has been developed on and tested against ARM-Mali GPU, but it is designed to work on any GPU conforming to OpenGL ES 2.0 or higher.

    The GPU involvement on future graphics is inevitable considering the pixel growth rate of displays, but harnessing the GPU power requires a different approach than CPU-based optimizations.

    read more

    By zoltan.herczeg at November 12, 2014 02:18 PM

    October 22, 2014

    Fuzzinator reloaded

    University of Szeged

    It's been a while since I last (and actually first) posted about Fuzzinator. Now I think that I have enough new experiences worth sharing.

    More than a year ago, when I started fuzzing, I was mostly focusing on mutation-based fuzzer technologies since they were easy to build and pretty effective. Having a nice error-prone test suite (e.g. LayoutTests) was the warrant for fresh new bugs. At least for a while.

    read more

    By renata.hodovan at October 22, 2014 10:38 PM

    September 25, 2014

    Measuring ASM.JS performance

    University of Szeged

    What is ASM.JS?

    Now that mobile computers and cloud services become part of our lives, more and more developers see the potential of the web and online applications. ASM.JS, a strict subset of JavaScript, is a technology that provides a way to achieve near native speed in browsers, without the need of any plugin or extension. It is also possible to cross-compile C/C++ programs to it and running them directly in your browser.

    In this post we will compare the JavaScript and ASM.JS performance in different browsers, trying out various kinds of web applications and benchmarks.

    read more

    By matyas.mustoha at September 25, 2014 10:40 AM

    August 28, 2014

    CSS Shapes now available in Chrome 37 release

    Adobe Web Platform

    Support for CSS Shapes is now available in the latest Google Chrome 37 release.


    What can I do with CSS Shapes?

    CSS Shapes lets you think out of the box! It gives you the ability to wrap content outside any shape. Shapes can be defined by geometric shapes, images, and even gradients. Using Shapes as part of your website design takes a visitor’s visual and reading experience to the next level. If you want to start with some tutorials, please go visit Sarah Soueidan’s article about Shapes.


    The following shapes use case is from the Good Looking Shapes Gallery blog post.

    Without CSS Shapes
    With CSS Shapes

    In the first picture, we don’t use CSS Shapes. The text wraps around the rectangular image container, which leads to a lot of empty space between the text and the visible part of the image.

    In the second picture, we use CSS Shapes. You can see the wrapping behavior around the image. In this case the white parts of the image are transparent, thus the browser can automatically wrap the content around the visible part, which leads to this nice and clean, visually more appealing wrapping behavior.

    How do I get CSS Shapes?

    Just update your Chrome browser to the latest version from the Chrome/About Google Chrome menu, or download the latest stable version from

    I’d like to thank the collaboration of WebKit and Blink engineers, and everyone else in the community who has contributed to this feature. The fact that Shapes is shipping in two production browsers — Chrome 37 now and Safari 8 later this year — is the upshot of the open source collaboration between the people who believe in a better, more expressive web. Although Shapes will be available in these browsers, you’ll need another solution for the other browsers. The CSS Shapes Polyfill is one method of achieving consistent behavior across browsers.

    Where should I start?

    For more info about CSS Shapes, please check out the following links:

    Let us know your thoughts or if you have nice demos, here or on Twitter: @AdobeWeb and @ZoltanWebKit.

    By Zoltan Horvath at August 28, 2014 05:12 PM

    May 13, 2014

    Good-Looking Shapes Gallery

    Adobe Web Platform

    As a modern consumer of media, you rarely crack open a magazine or a pamphlet or anything that would be characterized as “printed”. Let me suggest that you take a walk on the wild side. The next time you are in a doctor’s office, or a supermarket checkout lane, or a library, thumb though a magazine. Most of the layouts you’ll find inside can also be found on the web, but not all of them. Layouts where content hugs the boundaries of illustrations are common in print and rare on the web. One of the reasons non-rectangular contour-hugging layouts are uncommon on the web is that they are difficult to produce.

    They are not difficult to produce anymore.

    The CSS Shapes specification is now in the final stages of standardization. This feature enables flowing content around geometric shapes (like circles and polygons), as well as around shapes defined by an image’s alpha channel. Shapes make it easy to produce the kinds of layouts you can find in print today, with all the added flexibility and power that modern online media affords. You can use CSS Shapes right now with the latest builds of WebKit and Blink based browsers, like Safari and Chrome.

    Development of CSS Shapes has been underway for about two years, and we’ve been regularly heralding its progress here. Many of those reports have focused on the evolution of the spec and implementations, and they’ve included examples that emphasized basics over beauty. This article is an attempt to tilt the balance back towards good-looking. Listed below are simple shapes demos that we think look pretty good. Everyone on Adobe’s CSS Shapes engineering team contributed at least one.

    There’s a live version of each demo in the gallery. Click on the demo screenshot or one of the handy links to take a look. You’ll want to view the demos with a browser that supports Shapes and you’ll need to enable CSS Shapes in that browser. For example you can use a nightly build of the Safari browser or you can enable shapes in Chrome or Chrome Canary like this:

    1. Copy and paste chrome://flags/#enable-experimental-web-platform-features into the address bar, then press enter.
    2. Click the ‘Enable’ link within that section.
    3. Click the ‘Relaunch Now’ button at the bottom of the browser window.

    A few of the demos use the new Shapes Polyfill and will work in most browsers.

    And now, without further ado, please have a look through our good-looking shapes gallery.

    Ozma of Oz


    This demo reproduces the layout style that opens many of the chapters of the L. Frank Baum books, including Ozma of Oz.  The first page is often dominated by an illustration on the left or right. The chapter’s text conforms to the illustration, but not too tightly. The books were published over 100 years ago and they still look good print.  With CSS Shapes they can still look good on the web.

    Top Cap


    The conventional “drop-cap” opens a paragraph by enlarging and highlighting the first letter, word or phrase. The drop-cap’s goal is to draw your attention to where you can start reading. This demo delivers the same effect by crowning the entire opening paragraph with a “top cap” that funnels your attention into the article. In both cases, what’s going on is a segue from a graphic element to the text.



    A violator is small element that “violates” rectangular text layout by encroaching on a corner or a small part of an edge. This layout idiom is common in short-form magazines and product packaging. That “new and improved” banner which blazes through the corner of thousands of consumer products (whether or not they are new or improved) – it’s a violator.

    Column Interest


    When a print magazine feels the need to incorporate some column layout melodrama, they often reach for this idiom. The shape spans a pair of columns, which creates visual interest in the middle of the page. Without it you’d be faced with a wall of attention sapping text and more than likely turn the page.


    Screenshot of the wine jug caption demo.

    The old-school approach for including a caption with an image is to put the caption text alongside or below the image. Putting a caption on top of an image requires a little more finesse, since you have to ensure that the text doesn’t obscure anything important and that the text is rendered in a way that preserves readability.  The result can be relatively attractive.

    This photograph was taken by Zoltan Horvath who has pointed out that I’ve combined a quote about tea with a picture of a ceremonial wine jug.  I apologize for briefly breaching that beverage boundary. It’s just a demo.


    Screenshot of the paging demo.

    With a layout like this, one could simple let the content wrap and around the shape on the right and then expand into the usual rectangle.  In this demo the content is served up a paragraph at a time, in response to the left and right arrow keys.

    Note also: yes in fact the mate gourd is perched on exactly the same windowsill as the previous demo. Zoltan and Pope Francis are among the many fans of yerba mate tea.

    Ersatz shape-inside

    Screenshot of the ersatz shape-inside demo.

    Originally the CSS Shapes spec included shape-inside as well as shape-outside. Sadly, shape-inside was promoted to “Level 2″ of the spec and isn’t available in the current implementations. Fortunately for shape insiders everywhere, it’s still sometimes possible to mimic shape-inside with an adjacent pair of carefully designed shape-outside floats. This demo is a nice example of that, where the text appears inside a bowl of oatmeal.



    This is an animated demo, so to appreciate it you’ll really need to take a look at the live version. It is an example of using an animated shape to draw the user’s attention to a particular message.  Of course one must use this approach with restraint, since an animated loop on a web page doesn’t just gently tug at the user’s attention. It drags at their attention like a tractor beam.



    Advertisements are intended to grab the user’s attention and a second or two of animation will do that. In this demo a series of transition motions have been strung together into a tiny performance that will temporarily get the reader’s attention. The highlight of the performance is – of course – the text snapping into the robot’s contour for the finale. Try and imagine a soundtrack that punctuates the action with some whirring and clanking noises, it’s even better that way.

    By hmuller at May 13, 2014 05:38 PM

    April 24, 2014

    Adobe Web Platform Goes to the 2014 WebKit Contributors’ Meeting

    Adobe Web Platform

    Last week, Apple hosted the 2014 WebKit Contributors’ Meeting at their campus in Cupertino. As usual it was an unconference-style event, with session scheduling happening on the morning of the first day. While much of the session content was very specific to WebKit implementation, there were topics covered that are interesting to the wider web community. This post is a roundup of some of these topics from the sessions that Adobe Web Platform Team members attended.

    CSS Custom Properties for Cascading Variables

    Alan Stearns suggested a session on planning a new implementation of CSS Custom Properties for Cascading Variables. While implementations of this spec have been attempted in WebKit in the past, they never got past the experimental stage. Despite this, there is still much interest in implementing this feature. In addition, the current version of the spec has addressed many of the issues that WebKit contributors had previously expressed. We talked about a possible issue with using variables in custom property values, which Alan is investigating. More detail is available in the notes from the Custom Properties session.

    CSS Regions

    Andrei Bucur presented the current state of the CSS Regions implementation in WebKit. The presentation was well received and well attended. Notably, this was one of the few sessions with enough interest that it had a time slot all to itself.

    While CSS Regions shipped last year in iOS 7 and Safari 6.1 and 7, the implementation in WebKit hasn’t been standing still. Andrei mentioned the following short list of changes in WebKit since the last Safari release:

    • correct painting of fragments and overflow
    • scrollable regions
    • accelerated content inside regions
    • position: fixed elements
    • the regionoversetchange event
    • better selection
    • better WebInspector integration
    • and more…

    Andrei’s slides outlining the state of CSS Regions also contain a roadmap for the feature’s future in WebKit as well as a nice demo of the fix to fragment and overflow handling. If you are following the progress of CSS Regions in WebKit, the slides are definitely worth a look. (As of this writing, the Regions demo in the slides only works in Safari and WebKit Nightly.)

    CSS Shapes

    Zoltan Horvath, Bear Travis, and I covered the current state of CSS Shapes in WebKit. We are almost done implementing the functionality in Level 1 of the CSS Shapes Specification (which is itself a Candidate Recommendation, the last step before becoming an official W3C standard). The discussion in this session was very positive. We received good feedback on use cases for shape-outside and even talked a bit about the possibilities for when shape-inside is revisited as part of CSS Shapes Level 2. While I don’t have any slides or demos to share at the moment, we will soon be publishing a blog post to bring everyone up to date on the latest in CSS Shapes. So watch this space for more!

    Subpixel Layout

    This session was mostly about implementation. However, Zalan Bujtas drew an interesting distinction between subpixel layout and subpixel painting. Subpixel layout allows for better space utilization when laying out elements on the page, as boxes can be sized and positioned more precisely using fractional units. Subpixel painting allows for better utilization of high DPI displays by actually drawing elements on the screen using fractional CSS pixels (For example: on a 2x “Retina” display, half of a CSS pixel is one device pixel). Subpixel painting allows for much cleaner lines and smoother animations on high DPI displays when combined with subpixel layout. While subpixel layout is currently implemented in WebKit, subpixel painting is currently a work in progress.

    Web Inspector

    The Web Inspector is full of shiny new features. The front-end continues to shift to a new design, while the back-end gets cleaned up to remove cruft. The architecture for custom visual property editors is in place and will hopefully enable quick and intuitive editing of gradients, transforms, and animations in the future. Other goodies include new breakpoint actions (like value logging), a redesigned timeline, and IndexedDB debugging support. The Web Inspector still has room for new features, and you can always check out the #webkit-inspector channel on freenode IRC for the latest and greatest.

    Web Components

    The Web Components set of features continues to gather interest from the browser community. Web Components is made up of four different features: HTML Components, HTML Imports, Shadow DOM, and HTML Templates. The general gist of the talk was that the Web Components concepts are desirable, but there are concerns that the features’ complexity may make implementation difficult. The main concerns seemed to center around performance and encapsulation with Shadow DOM, and will hopefully be addressed with a prototype implementation of the feature (in the works). You can also take a look at the slides from the Web Components session.

    CSS Grid Layout

    The WebKit implementation of the CSS Grid Layout specification is relatively advanced. After learning in this session that the only way to test out Grid Layout in WebKit was to make a custom build with it enabled, session attendees concluded that it should be turned on by default in the WebKit Nightlies. So in the near future, experimenting with Grid Layout in WebKit should be as easy as installing a nightly build.


    As I mentioned earlier, this was just a high-level overview of a few of the topics at this year’s WebKit Contributors’ Meeting. Notes and slides for some of the topics not mentioned here are available on the 2014 WebKit Meeting page in the wiki. The WebKit project is always welcoming new contributors, so if you happen to see a topic on that wiki page that interests you, feel free to get in touch with the community and see how you can get involved.


    This post would not have been possible without the notes and editing assistance of my colleagues on the Adobe Web Platform Team that attended the meeting along with me: Alan Stearns, Andrei Bucur, Bear Travis, and Zoltan Horvath.

    By Bem Jones-Bey at April 24, 2014 05:23 PM

    March 18, 2014

    QtWebKit is no more, what now?

    Gustavo Noronha

    Driven by the technical choices of some of our early clients, QtWebKit was one of the first web engines Collabora worked on, building the initial support for NPAPI plugins and more. Since then we had kept in touch with the project from time to time when helping clients with specific issues, hardware or software integration, and particularly GStreamer-related work.

    With Google forking Blink off WebKit, a decision had to be made by all vendors of browsers and platform APIs based on WebKit on whether to stay or follow Google instead. After quite a bit of consideration and prototyping, the Qt team decided to take the second option and build the QtWebEngine library to replace QtWebKit.

    The main advantage of WebKit over Blink for engine vendors is the ability to implement custom platform support. That meant QtWebKit was able to use Qt graphics and networking APIs and other Qt technologies for all of the platform-integration needs. It also enjoyed the great flexibility of using GStreamer to implement HTML5 media. GStreamer brings hardware-acceleration capabilities, support for several media formats and the ability to expand that support without having to change the engine itself.

    People who are using QtWebKit because of its being Gstreamer-powered will probably be better served by switching to one of the remaining GStreamer-based ports, such as WebKitGTK+. Those who don’t care about the underlying technologies but really need or want to use Qt APIs will be better served by porting to the new QtWebEngine.

    It’s important to note though that QtWebEngine drops support for Android and iOS as well as several features that allowed tight integration with the Qt platform, such as DOM manipulation through the QWebElement APIs, making QObject instances available to web applications, and the ability to set the QNetworkAccessManager used for downloading resources, which allowed for fine-grained control of the requests and sharing of cookies and cache.

    It might also make sense to go Chromium/Blink, either by using the Chrome Content API, or switching to one its siblings (QtWebEngine included) if the goal is to make a browser which needs no integration with existing toolkits or environments. You will be limited to the formats supported by Chrome and the hardware platforms targeted by Google. Blink does not allow multiple implementations of the platform support layer, so you are stuck with what upstream decides to ship, or with a fork to maintain.

    It is a good alternative when Android itself is the main target. That is the technology used to build its main browser. The main advantage here is you get to follow Chrome’s fast-paced development and great support for the targeted hardware out of the box. If you need to support custom hardware or to be flexible on the kinds of media you would like to support, then WebKit still makes more sense in the long run, since that support can be maintained upstream.

    At Collabora we’ve dealt with several WebKit ports over the years, and still actively maintain the custom WebKit Clutter port out of tree for clients. We have also done quite a bit of work on Chromium-powered projects. Some of the decisions you have to make are not easy and we believe we can help. Not sure what to do next? If you have that on your plate, get in touch!

    By kov at March 18, 2014 07:44 PM

    February 25, 2014

    Improving your site’s visual details: CSS3 text-align-last

    Adobe Web Platform

    In this post, I want to give a status report regarding the text-align-last CSS3 property. If you are interested in taking control of the small visual details of your site with CSS, I encourage you to keep reading.

    The problem

    First, let’s talk about why we need this property. You’ve probably already seen many text blocks on pages that don’t quite seem visually correct, because the last line isn’t justified with the previous lines. Check out the example paragraph below:

    Example of the CSS3 text-align-last property

    In the first column, the last line isn’t justified. This is the expected behavior, when you apply the ‘text-align: justify’ CSS property on a container. On the other hand, in the second column, the content is entirely justified, including the last line.

    The solution

    This magic is the ‘text-align-last’ CSS3 property, which is set to justify on the second container. The text-align-last property is part of the CSS Text Module Level 3 specification, which is currently a working draft. The text-align-last property describes how the last line of a block or a line right before a forced line break is aligned when ‘text-align’ is ‘justify’, which means you gain full control over the alignment of the last line of a block. The property allows several more options, which you can read about on docs, or the CSS Text Module Level 3 W3C Specification.

    A possible use case (Added April – 2014)

    After looking at the previous example (which was rather focusing on the functionality of the property), let’s move on to a more realistic use case. The feature is perfect to make our multi-line captions look better. Check out the centered, and the justified image caption examples below.


    And now, compare them with a justified, multi-line caption, where the last line has been centered by text-align-last: center.

    I think the proper alignment of the last line gives a better overlook to the caption.

    Browser Support

    I recently added rendering support for the property in WebKit (Safari) based on the latest specification. Dongwoo Joshua Im from Samsung added rendering support in Blink (Chrome). If you like to try it out in WebKit, you’ll need to make a custom developer build and use the CSS3 text support build flag (--css3-text).

    The property is already included in Blink’s developer nightlies by default, so after launching your latest Chrome Canary, you only need to enable ‘Enable experimental Web Platform features’ under chrome://flags, and enjoy the full control over your last lines.

    Developer note

    Please keep in mind that both the W3C specification and the implementations are under experimental status. I’ll keep blogging about the feature and let you know if anything changes, including when the feature ships for production use!

    By Zoltan Horvath at February 25, 2014 04:58 PM

    January 05, 2014

    Funding MathML Developments in Gecko and WebKit (part 2)

    Frédéric Wang

    As I mentioned three months ago, I wanted to start a crowdfunding campaign so that I can have more time to devote to MathML developments in browsers and (at least for Mozilla) continue to mentor volunteer contributors. Rather than doing several crowdfunding campaigns for small features, I finally decided to do a single crowdfunding campaign with Ulule so that I only have to worry only once about the funding. This also sounded more convenient for me to rely on some French/EU website regarding legal issues, taxes etc. Also, just like Kickstarter it's possible with Ulule to offer some "rewards" to backers according to the level of contributions, so that gives a better way to motivate them.

    As everybody following MathML activities noticed, big companies/organizations do not want to significantly invest in funding MathML developments at the moment. So the rationale for a crowdfunding campaign is to rely on the support of the current community and on the help of smaller companies/organizations that have business interest in it. Each one can give a small contribution and these contributions sum up in enough money to fund the project. Of course this model is probably not viable for a long term perspective, but at least this allows to start something instead of complaining without acting ; and to show bigger actors that there is a demand for these developments. As indicated on the Ulule Website, this is a way to start some relationship and to build a community around a common project. My hope is that it could lead to a long term funding of MathML developments and better partnership between the various actors.

    Because one of the main demand for MathML (besides accessibility) is in EPUB, I've included in the project goals a collection of documents that demonstrate advanced Web features with native MathML. That way I can offer more concrete rewards to people and federate them around the project. Indeed, many of the work needed to improve the MathML rendering requires some preliminary "code refactoring" which is not really exciting or immediately visible to users...

    Hence I launched the crowdfunding campaign the 19th of November and we reached 1/3 of the minimal funding goal in only three days! This was mainly thanks to the support of individuals from the MathML community. In mid december we reached the minimal funding goal after a significant contribution from the KWARC Group (Jacobs University Bremen, Germany) with which I have been in communication since the launch of the campaign. Currently, we are at 125% and this means that, minus the Ulule commision and my social/fiscal obligations, I will be able to work on the project during about 3 months.

    I'd like to thank again all the companies, organizations and people who have supported the project so far! The crowdfunding campaign continues until the end of January so I hope more people will get involved. If you want better MathML in Web rendering engines and ebooks then please support this project, even a symbolic contribution. If you want to do a more significant contribution as a company/organization then note that Ulule is only providing a service to organize the crowdfunding campaign but otherwise the funding is legally treated the same as required by my self-employed status; feel free to contact me for any questions on the project or funding and discuss the long term perspective.

    Finally, note that I've used my savings and I plan to continue like that until the official project launch in February. Below is a summary of what have been done during the five weeks before the holiday season. This is based on my weekly updates for supporters where you can also find references to the Bugzilla entries. Thanks to the Apple & Mozilla developers who spent time to review my patches!

    Collection of documents

    The goal is to show how to use existing tools (LaTeXML, itex2MML, tex4ht etc) to build EPUB books for science and education using Web standards. The idea is to cover various domains (maths, physics, chemistry, education, engineering...) as well as Web features. Given that many scientific circles are too much biased by "math on paper / PDF" and closed research practices, it may look innovative to use the Open Web but to be honest the MathML language and its integration with other Web formats is well established for a long time. Hence in theory it should "just work" once you have native MathML support, without any circonvolutions or hacks. Here are a couple of features that are tested in the sample EPUB books that I wrote:

    • Rendering of MathML equations (of course!). Since the screen size and resolution vary for e-readers, automatic line breaking / reflowing of the page is "naturally" tested and is an important distinction with respect to paper / PDF documents.
    • CSS styling of the page and equations. This includes using (Web) fonts, which are very important for mathematical publishing.
    • Using SVG schemas and how they can be mixed with MathML equations.
    • Using non-ASCII (Arabic) characters and RTL/LTR rendering of both the text and equations.
    • Interactive document using Javascript and <maction>, <input>, <button> etc. For those who are curious, I've created some videos for an algebra course and a lab practical.
    • Using the <video> element to include short sequences of an experiment in a physics course.
    • Using the <canvas> element to draw graphs of functions or of physical measurements.
    • Using WebGL to draw interactive 3D schemas. At the moment, I've only adapted a chemistry course and used ChemDoodle to load Crystallographic Information Files (CIF) and provide 3D-representation of crystal structures. But of course, there is not any problem to put MathML equations in WebGL to create other kinds of scientific 3D schemas.


    I've finished some work started as a MathJax developer, including the maction support requested by the KWARC Group. I then tried to focus on the main goals: rendering of token elements and more specifically operators (spacing and stretching).

    • I improved LTR/RTL handling of equations (full RTL support is not implemented yet and not part of the project goal).
    • I improved the maction elements and implemented the toggle actiontype.
    • I refactored the code of some "mrow-like" elements to make them all behave like an <mrow> element. For example while WebKit stretched (some) operators in <mrow> elements it could not stretch them in <mstyle>, <merror> etc Similarly, this will be needed to implement correct spacing around operators in <mrow> and other "mrow-like" elements.
    • I analyzed more carefully the vertical stretching of operators. I see at least two serious bugs to fix: baseline alignment and stretch size. I've uploaded an experimental patch to improve that.
    • Preliminary work on the MathML Operator Dictionary. This dictionary contains various properties of operators like spacing and stretchiness and is fundamental for later work on operators.
    • I have started to refactor the code for mi, mo and mfenced elements. This is also necessary for many serious bugs like the operator dictionary and the style of mi elements.
    • I have written a patch to restore support for foreign objects in annotation-xml elements and to implement the same selection algorithm as Gecko.


    I've continued to clean up the MathML code and to mentor volunteer contributors. The main goal is the support for the Open Type MATH table, at least for operator stretching.

    • Xuan Hu's work on the <mpadded> element landed in trunk. This element is used to modify the spacing of equations, for example by some TeX-to-MathML generators.
    • On Linux, I fixed a bug with preferred widths of MathML token elements. Concretely, when equations are used inside table cells or similar containers there is a bug that makes equations overflow the containers. Unfortunately, this bug is still present on Mac and Windows...
    • James Kitchener implemented the mathvariant attribute (e.g used by some tools to write symbols like double-struck, fraktur etc). This also fixed remaining issues with preferred widths of MathML token elements. Khaled Hosny started to update his Amiri and XITS fonts to add the glyphs for Arabic mathvariants.
    • I finished Quentin Headen's code refactoring of mtable. This allowed to fix some bugs like bad alignment with columnalign. This is also a preparation for future support for rowspacing and columnspacing.
    • After the two previous points, it was finally possible to remove the private "_moz-" attributes. These were visible in the DOM or when manipulating MathML via Javascript (e.g. in editors, tree inspector, the html5lib etc)
    • Khaled Hosny fixed a regression with script alignments. He started to work on improvements regarding italic correction when positioning scripts. Also, James Kitchener made some progress on script size correction via the Open Type "ssty" feature.
    • I've refactored the stretchy operator code and prepared some patches to read the OpenType MATH table. You can try experimental support for new math fonts with e.g. Bill Gianopoulos' builds and the MathML Torture Tests.


    MathML developments in Chrome or Internet Explorer is not part of the project goal, even if obviously MathML improvements to WebKit could hopefully be imported to Blink in the future. Users keep asking for MathML in IE and I hope that a solution will be found to save MathPlayer's work. In the meantime, I've sent a proposal to Google and Microsoft to implement fallback content (alttext and semantics annotation) so that authors can use it. This is just a couple of CSS rules that could be integrated in the user agent style sheet. Let's see which of the two companies is the most reactive...

    By fredw at January 05, 2014 06:45 PM

    December 11, 2013

    WebKitGTK+ hackfest 5.0 (2013)!

    Gustavo Noronha

    For the fifth year in a row the fearless WebKitGTK+ hackers have gathered in A Coruña to bring GNOME and the web closer. Igalia has organized and hosted it as usual, welcoming a record 30 people to its office. The GNOME foundation has sponsored my trip allowing me to fly the cool 18 seats propeller airplane from Lisbon to A Coruña, which is a nice adventure, and have pulpo a feira for dinner, which I simply love! That in addition to enjoying the company of so many great hackers.

    Web with wider tabs and the new prefs dialog

    Web with wider tabs and the new prefs dialog

    The goals for the hackfest have been ambitious, as usual, but we made good headway on them. Web the browser (AKA Epiphany) has seen a ton of little improvements, with Carlos splitting the shell search provider to a separate binary, which allowed us to remove some hacks from the session management code from the browser. It also makes testing changes to Web more convenient again. Jon McCan has been pounding at Web’s UI making it more sleek, with tabs that expand to make better use of available horizontal space in the tab bar, new dialogs for preferences, cookies and password handling. I have made my tiny contribution by making it not keep tabs that were created just for what turned out to be a download around. For this last day of hackfest I plan to also fix an issue with text encoding detection and help track down a hang that happens upon page load.

    Martin Robinson and Dan Winship hack

    Martin Robinson and Dan Winship hack

    Martin Robinson and myself have as usual dived into the more disgusting and wide-reaching maintainership tasks that we have lots of trouble pushing forward on our day-to-day lives. Porting our build system to CMake has been one of these long-term goals, not because we love CMake (we don’t) or because we hate autotools (we do), but because it should make people’s lives easier when adding new files to the build, and should also make our build less hacky and quicker – it is sad to see how slow our build can be when compared to something like Chromium, and we think a big part of the problem lies on how complex and dumb autotools and make can be. We have picked up a few of our old branches, brought them up-to-date and landed, which now lets us build the main WebKit2GTK+ library through cmake in trunk. This is an important first step, but there’s plenty to do.

    Hackers take advantage of the icecream network for faster builds

    Hackers take advantage of the icecream network for faster builds

    Under the hood, Dan Winship has been pushing HTTP2 support for libsoup forward, with a dead-tree version of the spec by his side. He is refactoring libsoup internals to accomodate the new code paths. Still on the HTTP front, I have been updating soup’s MIME type sniffing support to match the newest living specification, which includes specification for several new types and a new security feature introduced by Internet Explorer and later adopted by other browsers. The huge task of preparing the ground for a one process per tab (or other kinds of process separation, this will still be topic for discussion for a while) has been pushed forward by several hackers, with Carlos Garcia and Andy Wingo leading the charge.

    Jon and Guillaume battling code

    Jon and Guillaume battling code

    Other than that I have been putting in some more work on improving the integration of the new Web Inspector with WebKitGTK+. Carlos has reviewed the patch to allow attaching the inspector to the right side of the window, but we have decided to split it in two, one providing the functionality and one the API that will allow browsers to customize how that is done. There’s a lot of work to be done here, I plan to land at least this first patch durign the hackfest. I have also fought one more battle in the never-ending User-Agent sniffing war, in which we cannot win, it looks like.

    Hackers chillin' at A Coruña

    Hackers chillin’ at A Coruña

    I am very happy to be here for the fifth year in a row, and I hope we will be meeting here for many more years to come! Thanks a lot to Igalia for sponsoring and hosting the hackfest, and to the GNOME foundation for making it possible for me to attend! See you in 2014!

    By kov at December 11, 2013 09:47 AM

    October 15, 2013

    Funding MathML Developments in Gecko and WebKit

    Frédéric Wang

    update 2013-10-15: since I got feedback, I have to say that my funding plan is independent of my work at MathJax ; I'm not a MathJax employee but I have an independent contractor status. Actually, I already used my business to fund an intern for Gecko MathML developments during Summer 2011 :-)


    Since last April, I have been allowed by the MathJax Consortium to dedicate a small amount of my time to do MathML development in browsers, until possibly more serious involvement later. At the same time, we mentioned this plan to Google developers but unfortunately they just decided to drop the WebKit MathML code from Blink, making external contributions hard and unwelcome...

    Hence I have focused mainly on Gecko and WebKit: You can find the MathML bugs that have been closed during that period on and For Gecko, this has allowed me to finish some of the work I started as a volunteer before I was involved full-time in MathJax as well as to continue to mentor MathML contributors. Regarding WebKit, I added a few new basic features like MathML lengths, <mspace> or <mmultiscripts> while I was getting familiar with the MathML code and WebKit organization/community. I also started to work on <semantics> and <maction>. More importantly, I worked with Martin Robinson to address the design concerns of Google developers and a patch to fix these issues finally landed early this week.

    However, my progress has been slow so as I mentioned in my previous blog post, I am planning to find a way to fund MathML developments...

    Why funding MathML?

    Note: I am assuming that the readers of this blog know why MathML is important and are aware of the benefits it can bring to the Web community. If not, please check Peter Krautzberger's Interview by Fidus Writer or the MozSummit MathML slides for a quick introduction. Here my point is to explain why we need more than volunteer-driven development for MathML.

    First the obvious thing: Volunteer time is limited so if we really want to see serious progress in MathML support we need to give a boost to MathML developments. e-book publishers/readers, researchers/educators who are stuck outside the Web in a LaTeX-to-PDF world, developers/users of accessibility tools or the MathML community in general want good math support in browsers now and not to wait again for 15 more years until all layout engines catch up with Gecko or that the old Gecko bugs are fixed.


    There are classical misunderstandings from people thinking that non-native MathML solutions and other polyfills are the future or that math on the Web could be implemented via PNG/SVG images or Web Components. Just open a math book and you will see that e.g. inline equations must be correctly aligned with the text or participate in line wrapping. Moreover we are considering math on the Web not math on paper, so we want it to be compatible with HTML, SVG, CSS, Javascript, Unicode, Bidi etc and also something that is fast and responsive. Technically, this means that a clean solution must be in the core rendering engine, spread over several parts of the code and must have strong interaction with the various components like the HTML5 parser, the layout tree, the graphic and font libraries, the DOM module, the style tree and so forth. I do not see any volunteer-driven Blink/Gecko/WebKit feature off the top of my head that has this characteristic and actually even SVG or any other kind of language for graphics have less interaction with HTML than MathML has.

    The consequence of this is that it is extremely difficult for volunteers to get involved in native MathML and to do quick progress because they have to understand how the various components of the Blink/Gecko/WebKit code work and be sure to do things correctly. Good mathematical rendering is already something hard by itself, so that is even more complicated when you are not writing an isolated rendering engine for math on which you can have full control. Also, working at the Blink/Gecko/WebKit level requires technical skills above the average so finding volunteers who can work with the high-minded engineers of the big browser companies is not something easy. For instance, among the enthusiastic people coming to me and willing to help MathML in Gecko, many got stuck when e.g. they tried to build the Firefox source or do something more advanced and I never heard back from them. In the other direction, Blink/Gecko/WebKit paid developers are generally not familiar with MathML and do not have time to learn more about it and thus can not always provide a relevant review of the code, or they may break something while trying to modify code they do not entirely understand. Moreover, both the volunteers and paid staff have only a small amount of time to do MathML stuff while the other parts of the engine evolve very quickly, so it's sometimes hard to keep everything in sync. Finally, the core layout engines have strong security requirements that are difficult to satisfy in a volunteer-driven situation...

    Beyond volunteer-driven MathML developments

    At that point, there are several options. First the lazy one: Give up with native math rendering, only focus on features that have impact on the widest Web audience (i.e. those that would allow browser vendors to get more market share and thus increase their profit), thank the math people for creating the Web and kindly ask them to use whatever hacks they can imagine to display equations on the Web. Of course as a Mozillian, I think people must decide the Web they want and thus exclude this option.

    Next there is the ingenuous option: Expect that browser companies will understand the importance of math-on-the-Web and start investing seriously in MathML support. However, Netscape and Microsoft rejected the <MATH> tag from the 1995 HTML 3.0 draft and the browser companies have kept repeating they would only rely on volunteer contributions to move MathML forward, despite the repeated requests from MathML folks and other scientific communities. So that option is excluded too, at least in the short to medium term.

    So it remains the ambitious option: Math people and other interested parties must get together and try to fund native MathML developments. Despite the effort of my manager at MathJax to convince partners and raise funds, my situation has not changed much since April and it is not clear when/if the MathJax Consortium can take the lead in native MathML developments. Given my expertise in Gecko, WebKit and MathML, I feel the duty to do something. Hence I wish to reorganize my work time: Decrease my involvement in MathJax core in order to increase my involvement in Gecko/WebKit developments. But I need the help of the community for that purpose. If you run a business with interest for math-on-the-Web and are willing to fund my work, then feel free to contact me directly by mail for further discussion. In the short term, I want to experiment with Crowd Funding as discussed in the next section. If this is successful we can think of a better organization for MathML developments in the long term.

    Crowd Funding

    Wikipedia defines Crowd funding as "the collective effort of individuals who network and pool their money, usually via the Internet, to support efforts initiated by other people or organizations". There are several Crowd Funding platforms with similar rule/interface. I am considering Catincan which is specialized in Open Source Crowd Funding, can be used by any backer/developer around the world, can rely on Bugzilla to track the bug status and seems to have good process to collect the fund from backers and to pay developers. You can easily login to the Catincan Website if you have a GitHub, Facebook or Google account (apparently Persona is not supported yet...). Finally, it seems to have a communication interface between backers and developers, so that everybody can follow the development on the funded features.

    One distinctive feature of catincan is that only well-established Open Source projects can be funded and only developers from these projects can propose and work on the new features ; so that backers can trust that the features will be implemented. Of course, I have been working on Gecko, WebKit and MathML projects so I hope people believe I sincerely want to improve MathML support in browsers and that I have the skills to do so ;-)

    As said in my previous blog post, it is not clear at all (at least to me) whether Crowd Funding can be a reliable method, but it is worth trying. There are many individuals and small businesses showing interest in MathML, without the technical knowledge or appropriate staff to improve MathML in browsers. So if each one fund a small amount of money, perhaps we can get something.

    One constraint is that each feature has 60 days to reach the funding goal. I do not have any idea about how many people are willing to contribute to MathML and how much money they can give. The statistical sample of projects currently funded is too small to extract relevant information. However, I essentially see two options: Either propose small features and split the big ones in small steps, so that each catincat submission will need less work/money and improvements will be progressive with regular feedback to backers ; or propose larger features so they look more attractive and exciting to people and will require less frequent submissions to catincat. At the beginning, I plan to start with the former and if the crowd funding is successful perhaps try the latter.

    Status in Open Source Layout Engines

    Note: Obviously, Open Source Crowd Funding does not apply to Internet Explorer, which is the one main rendering engine not mentioned below. Although Microsoft has done a great job on MathML for Microsoft Word, they did not give any public statement about MathML in Internet Explorer and all the bug reports for MathML have been resolved "by design" so far. If you are interested in MathML rendering and accessibility in Internet Explorer, please check Design Science blog for the latest updates and tools.


    Note: I am actually focusing on the history of Chromium here but of course there are other Blink-based browsers. Note that programs like QtWebEngine (formerly WebKit-based) or Opera (formerly Presto-based) lost the opportunity to get MathML support when they switched to Blink.

    Alex Milowski and François Sausset's first MathML implementation did not pass Google's security review. Dave Barton fixed many issues in that implementation and as far as I know, there were not any known security vulnerabilities when Dave submitted his last version. MathML was enabled in Chrome 24 but Chrome developers had some concerns about the design of the MathML implementation in WebKit, which indeed violated some assumptions of WebKit layout code. So MathML was disabled in Chrome 25 and as said in the introduction, the source code was entirely removed when they forked.

    Currently, the Chromium Dashboard indicates that MathML is shipped in Firefox/Safari, has positive feedback from developers and is an established standard ; but the Chromium status remains "No active development". If I understand correctly, Google's official position is that they do not plan to invest in MathML development but will accept external contributions and may re-enable MathML when it is ready (for some sense of "ready" to be defined). Given the MathML story in Chrome, it seems really unlikely that any volunteer will magically show up and be willing to submit a MathML patch. Incidentally, note the interesting work of the ChromeVox team regarding MathML accessibility: Their recent video provides a good overview of what they achieve (where Volker Sorge politely regrets that "MathML is not implemented in all browsers").

    Although Google's design concerns have now been addressed in WebKit, one most serious remark from one Google engineer is that the WebKit MathML implementation is of too low quality to be shipped so they just prefer to have no MathML at all. As a consequence, the best short term strategy seems to be improving WebKit MathML support and, once it is good enough, to submit a patch to Google. The immediate corollary is that if you wish to see MathML in Chrome or other Blink-based browsers you should help WebKit MathML development. See the next section for more details.

    Chromatic chromatic

    Actually, I tried to import MathML into Blink one day this summer. However, there were divergences between the WebKit and Blink code bases that made that a bit difficult. I do not plan to try again anytime soon, but if someone is interested, I have published my script and patch on GitHub. Note there may be even more divergences now and the patch is certainly bit-rotten. I also thought about creating/maintaining a "Chromatic" browser (Chrome + mathematics) that would be a temporary fork to let Blink users benefit from native MathML until it is integrated back in Blink. But at the moment, that would probably be too much effort for one person and I would prefer to focus on WebKit/Gecko developments for now.


    The situation in WebKit is much better. As said before, Google's concerns are now addressed and MathML will be enabled again in all WebKit releases soon. Martin Robinson is interested in helping the MathML developments in WebKit and his knowledge of fonts will be important to improve operator stretching, which is one of the biggest issue right now. One new volunteer contributor, Gurpreet Kaur, also started to do some work on WebKit like support for the *scriptshifts attributes or for the <menclose> element. Last but not least, a couple of Apple/WebKit developers reviewed and accepted patches and even helped to fix a few bugs, which made possible to move development forward.


    When he was still working on WebKit, Dave Barton opened bug 99623 to track the top priorities. When the bugs below and their related dependencies are fixed, I think the rendering in WebKit will be good enough to be usable for advanced math notations and WebKit will pass the MathML Acid 1 test.

    • Bug 44208: For example, in expression like sin(x), the "x" should be in italic but not the "sin". This is actually slightly more complicated: It says when the default mathvariant value must be normal/italic. mathvariant is more like the text-transform CSS property in the sense that it remaps some characters to the corresponding mathematical characters (italic, bold, fraktur, double-struck...) for example A (mathvariant=fraktur A) should render exactly the same as 𝔄 (U+1D504). By the way, there is the related bug 24230 on Windows, that prevents to use plane 1 characters. The best solution will probably be to implement mathvariant correctly. See also Gecko's ongoing work by James Kitchener below.
    • Bug 99618: Implement <mmultiscripts>, that allows expressions like C614 or Rij;j=12S;i. As said in the introduction, this is fixed in WebKit Nightly.
    • Bug 99614: Support for stretchy operators like in (z1+z2¯3)4. Currently, WebKit can only stretch operators vertically using a few Unicode constructions like ⎛ (U+239B) + ⎜ (U+239C) + ⎝ (U+239D) for the left parenthesis. Essentially only similar delimiters like brackets, braces etc are supported. For small sizes like ( or for large operators like n2 it is necessary to use non-unicode glyphs in various math fonts, but this is not possible in WebKit MathML yet. All of this will require a fair amount of work: implementing horizontal stretching, font-specific stuff, largeop/symmetric properties etc
    • Bug 99620: Implement the operator dictionary. Currently, WebKit treats all the operators the same way, so for example it will use the same 0.2em spacing before and after parenthesis, equal sign or invisible operators in e.g. f(x)=x2. Instead it should use the information provided by the MathML operator dictionary. This dictionary also specifies whether operators are stretchy, symmetric or largeop and thus is related to the previous point.
    • Bug 119038: Use the code for vertical stretchy operators to draw the radical symbols in roots like 23. Currently, WebKit uses graphic primitives which do not give a really good rendering.
    • Bug 115610: Implement <mspace> which is used by many MathML generators to do some spacing in mathematical formulas. As said in the introduction, this is fixed in WebKit Nightly.

    In order to pass the Mozilla MathML torture tests, at least displaystyle and scriptlevel must be implemented too, probably as internal CSS properties. This should also allow to pass Joe Java's MathML test, although that one relies on the infamous <mfenced> that duplicates the stretchy operator features and is implemented inconsistently in rendering engines. I think passing the MathML Acid 2 test will require slightly more effort, but I expect this goal to be achievable if I have more time to work on WebKit:

    • Bug 115610: Implement <mspace>. Fixed!
    • Bug 120164: Implement negative spacing for <mspace> (I have an experimental patch).
    • Bug 85730: Implement <mpadded>, which is also used by MathML generators to do some tweaking of formulas. I have only done some experiments, that would be a generalization of <mspace>
    • Bug 85733: Implement the href attribute ; well I guess the name is explicit enough to understand what it is used for! I only have some experimental patch here too. That would be mimicing what is done in SVG or HTML.
    • Bug 120059 and bug 100626: Implement <maction> (at least partially) and <semantics>, which have been asked by long-time MathML users Jacques Distler and Michael Kohlhase. I have patches ready for that and this could be fixed relatively soon, I just need to find time to finish the work.

    In general passing the MathML Acid 2 test is not too hard, you merely only need to implement those few MathML elements whose exact rendering is clearly defined by the MathML specification. Passing the MathML Acid 3 test is not expected in the medium term. However, the score will naturally increase while we improve WebKit MathML implementation. The priority is to implement what is currently known to be important to users. To give examples of bugs not previously mentioned: Implementing menclose or fixing various DOM issues like bugs 57695, 57696 or 107392.

    More advanced features like those mentioned in the next section for Gecko are probably worth considering later (Open type MATH, linebreaking, mlabeledtr...). It is worth noting that Apple has already done some work on accessibility (with MathML being readable by VoiceOver in iOS7), authoring and EPUB (MathML is enabled in WebKit-based ebook readers and ibooks-author has an integrated LaTeX-to-MathML converter).



    In general I think I have a good relationship with the Mozilla community and most people have respect for the work that has been done by volunteers for almost 15 years now. The situation has greatly improved since I joined the project, at that time some people claimed the Mozilla MathML project was dead after Roger Sidge's departure. One important point is that Karl Tomlinson has worked on repairing the MathML support when Roger Sidge left the project. Hence there is at least one Mozilla employee with good knowledge of MathML who can review the volunteer patches. Another key ingredient is the work that has recently been made by Mozilla to increase engagement of the volunteer community like good documentation on MDN, the #Introduction channel, Josh Matthews' mentored bugs and of course programs like GSOC. However, as said above, it is one thing to attract enthusiastic contributors and another thing to get long-term contributors who can work independently on more advanced features. So let's go back to my latest Roadmap for the Mozilla MathML Project and see what has been accomplished for one year:

    • Font support: Dmitry Shachnev created a Debian package for the MathJax fonts and Mike Hommey added MathJax and Asana fonts in the list of suggested packages for Iceweasel. The STIX fonts have also been updated in Fedora and are installed by default on Mac OS X Lion (10.7). For Linux distributions, it would be helpful to implement Auto Installation Support. The bug to add mathematical fonts to Android has been assigned in June but no more progress has happened so far. Henri Sinoven opened a bug for FirefoxOS but there has not been any progress there either. I had some patches to restore the "missing MathML fonts" warning (using an information bar) but it was refused by Firefox reviewers. However, the code to detect missing MathML font could still be used for the similar bug 648548, which also seems inactive since January. There are still some issues on the MathJax side that prevent to integrate Web fonts for the native MathML output mode. So at the moment the solution is still to inform visitors about MathML fonts or to add MathML Web fonts to your Web site. Khaled Hosny (font and LaTeX expert) recently updated my patches to prepare the support for Open Type fonts and he offered to help on that feature. After James Kitchener's work on mathvariant, we realized that we will probably need to provide Arabic mathematical fonts too.
    • Spacing: Xuan Hu continued to work on <mpadded> improvements and I think his patch is close to be accepted. Quentin Headen has done some progress on <mtable> before focusing on his InstantBird GSOC project. He is still far from being able to work on mtable@rowspacing/columnspacing but a work around for that has been added to MathJax. I fixed the negative space regression which was missing to pass the MathML Acid 2 test and is used in MathJax. Again, Khaled Hosny is willing to help to use the spacing of the Open Type MATH, but that will still be a lot of work.
    • <mlabeledtr>: A work around for native MathML has been added in MathJax.
    • Linebreaking: No progress except that I have worked on fixing a bug with intrinsic width computation. The unrelated printing issues mentioned in the blog post have been fixed, though.
    • Operator Stretching: No progress. I tried to analyze the regression more carefully, but nothing is ready yet.
    • Tabular elements: As said above, Quentin Headen has worked a bit on cleaning up <mtable> but not much improvements on that feature so far.
    • Token elements: My patch for <ms> landed and I have done significant progress on the bad measurement of intrinsic width for token elements (however, the fix only seems to work on Linux right now). James Kitchener has taken over my work on improving our mathvariant support and doing related refactoring of the code. I am confident that he will be able to have something ready soon. The primes in exponents should render correctly with MathJax fonts but for other math fonts we will have to do some glyph substitutions.
    • Dynamic MathML: No progress here but there are not so many bugs regarding Javascript+MathML, so that should not be too serious.
    • Documentation: It is now possible to use MathML in code sample or directly in the source code. The MathML project pages have been entirely migrated to MDN. Also, Florian Scholz has recently been hired by Mozilla as a documentation writer (congrats!) and will in particular continue the work he started as a volunteer to document MathML on MDN.

    I apologize to volunteers who worked on bugs that are not mentioned above or who are doing documentation or testing that do not appear here. For a complete list of activity since September 2012, Bugzilla is your friend. There are two ways to consider the progress above. If you see the glass half full, then you see that several people have continued the work on various MathML issues, they have made some progress and we now pass the MathML Acid 2 test. If you see the glass half empty, then you see that most issues have not been addressed yet and in particular those that are blocking the native MathML to be enabled in MathJax: bug 687807, bug 415413, the math font issues discussed in the first point, and perhaps linebreaking too. That is why I believe we should go beyond volunteer-driven MathML developments.

    Most of the bugs mentioned above are tested by the MathML Acid 3 tests and we will win a few points when they are fixed. Again, passing MathML Acid 3 test is not a goal by itself so let's consider what are the big remaining areas it contains:

    • Improving Tabular Elements and Operator Stretching, which are obviously important and used a lot in e.g. MathJax.
    • Linebreaking, which as I said is likely to become fundamental with small screens and ebooks.
    • Elementary Mathematics (you know addition, subtraction, multiplication, and division that kids learn), which I suspect will be important for educational tools and ebooks.
    • Alignment: This is the one part of MathML that I am not entirely sure is relevant to work on in the short term. I understand it is useful for advanced layout but most MathML tools currently just rely on tables to do that job and as far as I know the only important engine that implements that is MathPlayer.

    Finally there are other features outside the MathML rendering engines that I also find important but for which I have less expertise:

    • Transferring MathML that is implementing copy/cut/drag and paste. Currently, we can do that by treating MathML as normal HTML5 code or by using the "show MathML source" feature and copying the source code. However, it would be best to implement a standard way to communicate with other MathML applications like Microsoft Word, Mathematica, Mapple, Windows' Handwriting panel etc I wrote some work-in-progress patches last year.
    • Authoring MathML: Essentially implementing things like deletion, insertion etc maybe simple MathML token creation ; in Gecko's core editor, which is used by BlueGriffon, KompoZer, SeaMonkey, Thunderbird or even MDN. Other things like integrating Javascript parsers (e.g. ASCIIMath) or equation panels with buttons like are probably better done at the higher JS/HTML/XUL level. Daniel Glazman already wrote math input panels for BlueGriffon and Thunderbird.
    • MathML Accessibility: This is one important application of MathML for which there is strong demand and where Mozilla is behind the competitors. James Teh started some experimental work on his NVDA tool before the summit.
    • EPUB reader for FirefoxOS (and other mobile platforms): During the "Co-creating Action Plans" session, the Mozilla Taipei people were thinking about missing features for FirefoxOS and this idea about EPUB reader was my modest contribution. There are a few EPUB readers relying on Gecko and it would be good to check if they work in FirefoxOS and if they could be integrated by default, just like Apple has iBooks. BTW, there is a version of BlueGriffon that can edit EPUB books.


    I hope I have convinced some of the readers about the need to fund MathMLin browsers. There is a lot of MathML work to do on Gecko and WebKit but both projects have volunteers and core engineers who are willing to help. There are also several individuals / companies relying on MathML support in rendering engines for their projects and could support the MathML developments in some way. I am willing to put more of my time on Gecko and WebKit developments, but I need financial help for that purpose. I'm proposing catincan Crowd Funding in the short term so that anyone can contribute at the appropriate level, but other alternatives to fund the MathML development can be found like asking Peter Krautzberger about native MathML funding in MathJax, discussing with Igalia about funding Martin Robinson to work more on WebKit MathML or contacting me directly to establish some kind of part-time consulting agreement.

    Please leave a comment on this blog or send me a private mail, if you agree that funding MathML in browsers is important, if you like the crowd funding idea and plan to contribute ; or if you have any opinions about alternative funding options. Also, please tell me what seem to be the priority for you and your projects among what I have mentioned above (layout engines, features etc) or among others that I may have forgotten. Of course, any other constructive comment to help MathML support in browsers is welcome. I plan to submit features on catincan soon, once I have more feedback on what people are interested in. Thank you!

    By fredw at October 15, 2013 08:05 PM

    October 07, 2013

    Post-Summit Thoughts on the MathML Project

    Frédéric Wang

    I'm back from a great Mozilla Summit 2013 and I'd just like to write a quick blog post about the MathML booths at the Innovation Fairs. I did not have the opportunity to talk with the MathML people who ran the booth at Santa Clara yet. However, everything went pretty well at Brussels, modulo of course some demos failing when done in live... If you are interested, the slides and other resources are available on my GitHub page.

    Many Mozillians did not know about MathML or that it had been available in Gecko since the early days of the Mozilla project. Many people who use math (or just knowing someone who does) were curious about that feature and excited about the MathML potentials. I appreciated to get this positive feedback from Mozillians willing to use math on the Web and related media, instead of the scorn or hatred I sometimes see by misinformed people. I expect to provide more updates on LaTeXML, MediaWiki Math and MathJax when their next versions are released. The Gecko MathML support improves slowly but there has been interesting work by James Kitchener recently that I'd like to mention too.

    MathZilla on blackboard

    Let's do an estimation à la Fermi: only a few volunteers have been contributing regularly and simultaneously to MathML in Gecko while most Mozilla-funded Gecko projects have certainly development teams that are 3 times as large. Let's be optimistic and assume that these volunteers have been able to dedicate a mean of 1 work day per week, compared to 5 for full-time staff. Given that the Mozilla MathML project will celebrate its 15 years next May, that means that the volunteer work transposed in terms of paid-staff time is only 15 35 = 1 year. To be honest, I'm disregarding here the great work made by the Mozilla NZ team around 2007 to repair MathML after the Cairo migration. But still, what we have achieved in quality and completeness with such limited resources and time is really impressive.

    As someone told me at the MathML booth, it's really frustating that something that is so important for the small portion of math-educated people is ignored because it is useless for the vast majority of people. This is not entirely true, since even elementary mathematics taught at school like the one of this blog post are not easily expressed with standard HTML and even less in a way accessible to people with visual disabilities. However, it summarizes well the feeling MathML folks had when they tried to convince Google to accept the volunteer work on MathML, despite its low quality.

    As explained at the Summit Sessions, Mozilla's mission is different and the goal is to give people the right to control the Web they want. The MathML project is perhaps one of the oldest and successful volunteer-driven Mozilla project that is still active and demonstrates concretely the idea of the Mozilla's mission with e.g. the work of Roger Sidge who started to write the MathML implementation when Netscape opened its source code or the one of Florian Scholz who made MDN one of the most complete Web resource for MathML.

    Mozilla Corporation has kept saying they don't want to invest in MathML developments and the focus right now is clearly on other features like FirefoxOS. Even projects that have a larger audience than the MathML support like the mail client or the editor are not in the priorities so someone else definitely need to step in for MathML. I've tried various methods, with more or less success, to boost the MathML developments like mentoring a GSoC project, funding a summer internship or relying on mentored bugs. I'm now considering crowd funding to help the MathML developments in Gecko (and WebKit). I don't want to do another Fermi estimation now but at first that looks like a very unreliable method. The only revenue generated by the MathML project so far are the 2 100 π 100 = 2 3.14 = 6.28 dollars to the Mozilla Fundation via contributions to my MathML-fonts add-on, so it's hard to get an idea of how much people would contribute to the Gecko implementaton. However, that makes sense since the only people who showed interest in native MathML support so far are individuals or small businesses (e.g. working on EPUB or accessibility) and I think it's worth trying it anyway. That's definitely something I'll consider after MathJax 2.3 is released...

    By fredw at October 07, 2013 04:18 PM

    August 27, 2013

    HTML Alchemy – Combining CSS Shapes with CSS Regions

    Adobe Web Platform

    Note: Support for shape-inside is only available until the following nightly builds: WebKit r166290 (2014-03-26); Chromium 260092 (2014-03-28).

    I have been working on rendering for almost a year now. Since I landed the initial implementation of Shapes on Regions in both Blink and WebKit, I’m incredibly excited to talk a little bit about these features and how you can combine them together.


    Don’t know what CSS Regions and Shapes are? Start here!

    The first ingredient in my HTML alchemy kitchen is CSS Regions. With CSS Regions, you can flow content into multiple styled containers, which gives you enormous creative power to make magazine style layouts. The second ingredient is CSS Shapes, which gives you the ability to wrap content inside or outside any shape. In this post I’ll talk about the “shape-inside” CSS property, which allows us to wrap content inside an arbitrary shape.

    Let’s grab a bowl and mix these two features together, CSS Regions and CSS Shapes to produce some really interesting layouts!

    In the latest Chrome Canary and Safari WebKit Nightly, after enabling the required experimental features, you can flow content continuously through multiple kinds of shapes. This rocks! You can step out from the rectangular text flow world and break up text into multiple, non-rectangular shapes.


    If you already have the latest Chrome Canary/Safari WebKit Nightly, you can just go ahead and try a simple example on If you are too lazy, or if you want to extend your mouse button life by saving a few button clicks, you can continue reading.


    In the picture above we see that the “Lorem ipsum” story flows through 4 different, colorful regions. There is a circle shape on each of the first two fixed size regions. Check out the code below to see how we apply the shape to the region. It’s pretty straightforward, right?
    #region1, #region2 {
        -webkit-flow-from: flow;
        background-color: yellow;
        width: 200px;
        height: 200px;
        -webkit-shape-inside: circle(50%, 50%, 50%);
    The content flows into the third (percentage sized) region, which represents a heart (drawn by me, all rights reserved). I defined the heart’s coordinates in percentages, so the heart will stretch as you resize the window.
    #region3 {
        -webkit-flow-from: flow;
        width: 50%;
        height: 400px;
        background-color: #EE99bb;
        -webkit-shape-inside: polygon(11.17% 10.25%,2.50% 30.56%,3.92% 55.34%,12.33% 68.87%,26.67% 82.62%,49.33% 101.25%,73.50% 76.82%,85.17% 65.63%,91.63% 55.51%,97.10% 31.32%,85.79% 10.21%,72.47% 5.35%,55.53% 14.12%,48.58% 27.88%,41.79% 13.72%,27.50% 5.57%);

    The content that doesn’t fit in the first three regions flows into the fourth region. The fourth region (see the retro-blue background color) has its CSS width and height set to auto, so it grows to fit the remaining content.

    Real world examples

    After trying the demo and checking out the links above, I’m sure you’ll see the opportunities for using shape-inside with regions in your next design. If you have some thoughts on this topic, don’t hesitate to comment. Please keep in mind that these features are under development, and you might run into bugs. If you do, you should report them on WebKit’s Bugzilla for Safari or Chromium’s issue tracker for Chrome. Thanks for reading!

    By Zoltan Horvath at August 27, 2013 04:00 PM

    August 06, 2013

    WebGL, at last!

    Brent Fulgham

    It's been a long time since I've written an update -- but my lack of blog posting is not an indication of a lack of progress in WebKit or the WinCairo port. Since I left my former employer (who *still* hasn't gotten around to updating the build machine I set up there), we've:

    • Migrated from Visual Studio 2005 to Visual Studio 2010 (and soon, VS2012)
    • Enabled New-run-webkit-tests
    • Updated the WinCairo Support Libraries to support 64-bit builds
    • Integrated a ton of cURL improvements and extensions thanks to the TideSDK guys 
    • and ...
    ... thanks to the hard work of Alex Christensen, brought up WebGL on the WinCairo port.  This is a little exciting for me, because it marks the first time (I can recall) where the WinCairo port actually gained a feature that was not already part of the core Apple Windows port.

    The changes needed to see these circa-1992 graphics in all their three-dimensional glory are already landed in the WebKit tree.  You just need to:

    1. Enable the libEGL, libGLESv2, translator_common, translator_glsl, and translator_hlsl for the WinCairo build (they are currently turned off).
    2. Make the following change to WTF/wtf/FeatureDefines.h: 

    Brent Fulgham@WIN7-VM ~/WebKit/Source/WTF/wtf
    $ svn diff
    Index: FeatureDefines.h
    --- FeatureDefines.h    (revision 153733)
    +++ FeatureDefines.h    (working copy)
    @@ -245,6 +245,13 @@

    +#define ENABLE_WEBGL 1
    +#define WTF_USE_3D_GRAPHICS 1
    +#define WTF_USE_OPENGL 1
    +#define WTF_USE_OPENGL_ES_2 1
    +#define WTF_USE_EGL 1
     #endif /* PLATFORM(WIN_CAIRO) */

     /* --------- EFL port (Unix) --------- */

    Performance is a little ragged, but we hope to improve that in the near future.

    We have plenty of more plans for the future, including full 64-bit support (soon), and hopefully some improvements to the WinLauncher application to make it a little more useful.

    As always, if you would like to help out,

    By Brent Fulgham ( at August 06, 2013 05:53 AM

    May 15, 2013

    CSS Level 3 Text Decoration on WebKit and Blink – status

    Bruno de Oliveira Abinader

    It’s been a while since I wrote the last post about progress on implementing CSS Level 3 Text Decoration features in WebKit. I’ve been involved with other projects but now I can finally resume the work in cooperation with my colleague from basysKom, Lamarque Souza. So far we have implemented:

    • text-decoration-line (link)
    • text-decoration-style (link)
    • text-decoration-color (link)
    • text-underline-position (link)

    These properties are currently available under -webkit- prefix on WebKit, and guarded by a feature flag - CSS3_TEXT – which is enabled by default on both EFL and GTK ports. On Blink, plans are to get these properties unprefixed and under a runtime flag, which can be activated by enabling the “Experimental WebKit Features” (updated to “Experimental Web Platform Features” in latest builds) flag – see chrome://flags inside Google Chrome/Chromium). There are still some Skia-related issues to fix on Blink to enable proper dashed and dotted text decoration styles to be displayed. In the near future, we shall also have the text-decoration shorthand as specified on CSS Level 3 specification.

    See below a summary of things I plan to finish in the near future:

    • [webkit] Property text-decoration-line now accepts blink as valid value
    • [blink] Fix implementation of dashed and dotted styles on Skia
    • [blink] Fix an issue where previous Skia stroke styles were used when rendering paint decorations
    • [blink] Implement CSS3_TEXT as a runtime flag
    • [blink] Property text-decoration-line now accepts blink as valid value
    • [blink] Implement support for text-decoration shorthand
    • [webkit] Implement support for text-decoration shorthand

    Note: Please do not confuse text-decoration‘s blink value with Blink project :)

    Stay tuned for further updates!

    By Bruno Abinader at May 15, 2013 04:52 PM

    May 03, 2013

    Firefox Nightly passes the Acid2 test

    Frédéric Wang

    Some updates on the MathML Acid Tests... First the patch for bug 717546 landed in Nightly and thus Gecko is now the first layout engine to pass the MathML Acid2 test. Here is a screenshot that should look familiar:

    MathML Acid2, Nightly

    As you know, Google developers forked Webkit and decided to remove from Blink all the code (including MathML) on which they don't plan to work in the short term. As a comparison, here is how the MathML Acid2 test looks like in Chrome Canary:

    MathML Acid 2 Test, Canary

    Next, someone reported that Firefox Mac got more errors in the MathML Acid3 test. I was already aware of some shortcomings anyway and thus took the opportunity to rewrite the tests with a better error tolerance. The changes also fixed some measurement issues with auto resizing on mobile platforms or when the zoom level is not set to the default. I also made the tests for stretchy operators more reliable and as a consequence, Gecko lost two points: the new score is 60/100. I still need to review and describe the tests and hope I won't find more mistakes.

    Finally, I also added a MathML Acid1 test. It does not really look like the "classical" Acid1 test and is not "automated", in the sense that a reader must carefully (and in a subjective way) check the basic requirements. But at least it provides a small test in the spirit of CSS Acid 1: all 100%-conformant HTML 5 agents should be able to render these very elementary MathML expressions. Note that the formulas in the MathML Acid1 test are supposed to express mathematical properties of boxes from the CSS Acid1 test.

    By fredw at May 03, 2013 12:43 PM

    March 27, 2013

    Freeing the Floats of the Future From the Tyranny of the Rectangle

    Adobe Web Platform

    With modern web layout you can have your content laid out in whatever shape you want as long as it’s a rectangle. Designers in other media have long been able to have text and other content lay out inside and around arbitrarily complex shapes. The CSS Exclusions, CSS Shapes Level 1, and CSS Shapes Level 2 specifications aim to bring this capability to the web.

    While these features aren’t widely available yet, implementation is progressing and it’s already possible to try out some of the features yourself. Internet Explorer 10 has an implementation of the exclusions processing model, so you can try out exclusions in IE 10 today.

    At Adobe we have been focusing on implementing the shapes specification. We began with an implementation of shape-inside and now have a working implementation of the shape-outside property on floats. We have been building our implementation in WebKit, so the easiest way to try it out yourself is to download a copy of Chrome Canary. Once you have Canary, enable Experimental Web Platform Features and go wild!

    What is shape-outside?

    “Now hold up there,” you may be thinking, “I don’t even know what a shape-outside is and you want me to read this crazy incomprehensible specification thing to know what it is!?!”

    Well you’ll be happy to know that it really isn’t that complex, especially in the case of floats. When an element is floated, inline content avoids the floated element. Content flows around the margin box of the element as defined by the CSS box model. The shape-outside CSS property allows you to tell the browser to use a specified shape instead of the margin box when wrapping content around the floating element.

    CSS Exclusions

    The current implementation allows for rectangles, rounded rectangles, circles, ellipses, and polygons. While this gives a lot of flexibility, eventually you will be able to use a SVG path or the alpha channel of an image to make it easier to create complex shapes.

    How do I use it?

    First, you need to get a copy of Chrome Canary and then enable Experimental Web Platform features. Once you have that, load up this post in Chrome Canary so that you can click on the images below to see a live example of the code. Even better, the examples are on Codepen, so you can and should play with them yourself and see what interesting things you can come up with.

    Note that in this post and the examples I use the unprefixed shape-outside property.
    If you want to test these examples outside of my Codepen then you will need to use the prefixed -webkit-shape-outside property or use (which is a built in option in Codepen).

    We’ll start with a HTML document with some content and a float. Currently shape-outside only works on floating elements, so those are the ones to concentrate on. For example: (click on the image to see the code)

    HTML without shape-outside

    You can now add the shape-outside property to the style for your floats.

    .float {
      shape-outside: circle(50%, 50%, 50%);

    A circle is much more interesting than a standard rectangle, don’t you think? This circle is centered in the middle of the float and has a radius that is half the width of the float. The effect on the layout is something like this:

    shape-outside circle

    While percentages were used for this circle, you can use any CSS unit you like to specify the shape. All of the relative units are relative to the dimensions of element where the shape-outside is specified.

    Supported shapes

    Circles are cool and all, but I promised you other shapes, and I will deliver. There are four types of shapes that are supported by the current shape-outside implementation: rectangle, circle, ellipse, and polygon.


    You have the ability to specify a shape-outside that is a fairly standard rectangle:

    shape-outside: rectangle(x, y, width, height);

    The x and y parameters specify the coordinates of the top-left corner of the rectangle. This coordinate is in relation to the top-left corner of the floating element’s content box. Because of the way this interacts with the rules of float positioning, setting these to anything other than 0 causes an effect that is similar to relatively positioning the float’s content. (Explaining this is beyond the scope of this post.)

    The width and height parameters should be self-explanatory: they are the width and height of the resulting rectangle.

    Where things get interesting is with the six-argument form of rectangle:

    shape-outside: rectangle(x, y, width, height, rx, ry);

    The first four arguments are the same as explained above, but the last two specify corner radii in the horizontal (rx) and vertical (ry) directions. This not only allows the creation of rounded rectangles, you can create circles and ellipses as well. (Just like with [border-radius][border-radius].)

    Here’s an example of a rectangle, a rounded rectangle, a circle, and an ellipse using just rectangle syntax:

    shape-outside rectangle

    If you’re reading this in Chrome Canary with exclusions turned on, play around with this demo and see what other things you can do with the rectangles.


    I already showed you a simple circle demo and you’ll be happy to know that’s pretty much all there is to know about circles:

    shape-outside: circle(cx, cy, radius);

    The cx and cy parameters specify the coordinates of the center of the circle. In most situations you’ll want to put them at the center of your box. Just like with rectangles moving this around can be useful, but it behaves similarly to relatively positioning the float’s content with respect to the shape.

    The radius parameter is the radius of the resulting circle.

    In case you’d like to see it again, here’s what a circle looks like:

    shape-outside circle

    While it is possible to create circles with rounded rectangles as described above, having a dedicated circle shape is much more convenient.


    Sometimes, you need to squish your circles and that’s where the ellipse comes in handy.

    shape-outside: ellipse(cx, cy, rx, ry);

    Just like a circle, an ellipse has cx and cy to specify the coordinates of its center and you will likely want to have them at the center of your float. And just like all the previous shapes, changing these around will cause the float’s content to position relative to your shape.

    The rx and ry parameters will look familiar from the rounded rectangle case and they are exactly what you would expect: the horizontal and vertical radii of the ellipse.

    Ellipses can be used to create circles (rx = ry) and rounded rectangles can be used to create ellipses, but it’s best to use the shape that directly suits your purpose. It’s much easier to read and maintain that way.

    Here’s an example of using an ellipse shape:

    shape-outside ellipse


    Now here’s where things get really interesting. The polygon `shape-outside` allows you to specify an arbitrary polygonal shape for your float:

    shape-outside: polygon(x1 y1, x2 y2, ... , xn yn);

    The parameters of the polygon are the x and y coordinates of each vertex of the shape. You can have as many vertices as you would like.

    Here’s an example of a simple polygon:

    shape-outside triangle

    Feel free to play with this and see what happens if you create more interesting shapes!

    Putting content in the float

    The previous examples all had divs without any content just to make it easier to read and understand the code, but a big motivation for shape-outside is to wrap around other content. Interesting layouts often involve wrapping text around images as this final example shows:

    shape-outside with images

    As usual, you should take a look and play with the code for this example of text wrapping around floated images. This is just the beginning of the possibilities, as you can put a shape outside on any floating element with any content you want inside.

    Next steps

    We are still hard at work on fixing bugs in the current implementation and implementing the rest of the features in the CSS Shapes Level 1 specification. We welcome your feedback on what is already implemented and also on the spec itself. If you are interested in becoming part of the process, you can raise issues with the current WebKit implementation by filing bugs in the WebKit bugzilla. If you have issues with the spec, those are best raised on the www-style mailing list. And of course, you can leave your feedback as comments on this post.

    I hope that you enjoy experimenting with shape-outside and the other features we are currently working on.

    By Bem Jones-Bey at March 27, 2013 05:10 PM

    March 02, 2013

    MathML Acid Tests

    Frédéric Wang

    There has recently been discussion in the Mozilla community about Opera switch from Presto to Webkit and the need to preserve browser competition and diversity of rendering engines, especially with mobile devices. Some people outside the community seem a bit skeptic about that argument. Perhaps a striking example to convince them is to consider the case of MathML where basically only Gecko has a decent native implementation and the situation in the recent eBooks workshop illustrates that very well: MathML support is very important for some publishers (e.g. for science or education) but the main eBook readers rely exclusively on the Webkit engine and its rudimentary MathML implementation. Unfortunately because there is currently essentially no alternatives on mobile platforms, developers of eBook readers have no other choices than proposing a partial EPUB support or relying on polyfill....

    After Google's announce to remove MathML from Chrome 25, someone ironized on twitter about the fact that an Acid test for MathML should be written since that seems to motivate them more than community feedback. I do not think that MathML support is something considered important from the point of view of browser competition but I took this idea and started writing MathML versions of the famous Acid2 and Acid3 tests. The current source of these MathML Acid tests is available on GitHub. Of course, I believe that native MathML implementation is very important and I expect at least that these tests could help the MathML community ; users and implementers.

    Here is the result of the MathML Acid2 test with the stable Gecko release. To pass the test we only need to implement negative spacing or at least integrate the patch I submitted when I was still active in Gecko developments (bug 717546).

    MathML Acid2 test ; Gecko

    And here is the score of the MathML Acid 3 test with the stable Gecko release. The failure of test 18 was not supposed to happen but I discovered it when I wrote the test. That will be fixed by James Kitchener's refactoring in bug 827713. Obviously, reaching the score of 100/100 will be much more difficult to achieve by our volunteer developers, but the current score is not too bad compared to other rendering engines...

    MathML Acid 3 ; Gecko

    By fredw at March 02, 2013 06:19 PM

    January 11, 2013

    MathML in Chrome, a couple of demos and some perspectives...

    Frédéric Wang

    For those who missed the news, Google Chrome 24 has recently been released with native MathML support. I'd like to thank Dave Barton again for his efforts during the past year, that have allowed to make this happen. Obviously, some people may ironize on how long it took for Google to make this happen (Mozilla MathML project started in 1999) or criticize the bad rendering quality. However the MathML folks, aware of the history of the language in browsers, will tend to be more tolerant and appreciate this important step towards MathML adoption. After all, this now means that among the most popular browsers, Firefox, Safari and Chrome have MathML support and Opera a basic CSS-based implementation. This also means that about three people out of four will be able to read pages with MathML without the need of any third-party rendering engine.

    After some testing, I think the Webkit MathML support is now good enough to be used on my Website. There are a few annoyances with stretchy characters or positioning, but in general the formulas are readable. Hence in order to encourage the use of MathML and let people report bugs upstream and hopefully help to fix them, I decided to rely on the native MathML support for Webkit-based browsers. I'll still keep MathJax for Internet Explorer (when MathPlayer is not installed) and Opera.

    I had the chance to meet Dave Barton when I was at the Silicon Valley last October for the GSoC mentor summit. We could exchange our views on the MathML implementations in browsers and discuss the perspectives for the future of MathML. The history of MathML in Webkit is actually quite similar to Gecko's one: one volunteer Alex Milowski decided to write the initial implementation. This idea attracted more volunteers who joined the effort and helped to add new features and to conduct the project. Dave told me that the initial Webkit implementation did not pass the Google's security review and that's why MathML was not enabled in Chrome. It was actually quite surprising that Apple decided to enable it in Safari and in particular all Apple's mobile products. Dave's main achievement has been to fix all these security bugs so that MathML could finally appear in Chrome.

    One of the idea I share with Dave is how important it is to have native MathML support in browsers, rather than to delegate the rendering to Javascript libraries like MathJax or browser plug-in like MathPlayer. That's always a bit sad to see that third-party tools are necessary to improve the native browser support of a language that is sometimes considered a core XML language for the Web together with XHTML and SVG. Not only native support is faster but also it integrates better in the browser environment: zooming text, using links, applying CSS style, mixing with SVG diagrams, doing dynamic updates with e.g. Javascript etc all of the features Web users are familiar with are immediately available. In order to illustrate this concretely, here is a couple of demos. Some of them are inspired from the Mozilla's MathML demo pages, recently moved to MDN. By the way, the famous MathML torture page is now here. Also, try this test page to quickly determine whether you need to install additional fonts.

    MathML with CSS text-shadow & transform properties, href & dir attributes as well as Javascript events

    det ( 1 2 3 4 5 6 7 8 9 ) = 45 + 84 + 96 ( 105 + 48 + 72 ) = 0 محدد ( ١‎ ٢ ٣ ٤ ٥ ٦ ٧‎ ٨ ٩ ) = ٤٥ + ٨٤ + ٩٦ ( ١‎٠٥ + ٤٨ + ٧‎٢ ) = ٠

    HTML and animated SVG inside MathML tokens

    tr ( ) n = = 0 π 2 θ θ

    MathML inside animated SVG (via the <foreignObject> element):

    <foreignObject width="60" height="60"> n = 0 + α n n ! </foreignObject> exp(α)

    Note that although Dave was focused on improving MathML, the language naturally integrates with the rest of Webkit's technologies and almost all the demos above work as expected, without any additional efforts. Actually, Gecko's MathML support relies less on the CSS layout engine than Webkit does and this has been a recurrent source of bugs. For example in the first demo, the text-shadow property is not applied to some operators (bug 827039) while it is in Webkit.

    In my opinion, one of the problem with MathML is that the browser vendors never really shown a lot of interest in this language and the standardization and implementation efforts were mainly lead and funded by organizations from the publishing industry or by volunteer contributors. As the MathML WG members keep repeating, they would love to get more feedback from the browser developers. This is quite a problem for a language that has among the main goal the publication of mathematics on the Web. This leads for example to MathML features (some of them are now deprecated) duplicating CSS properties or to the <mstyle> element which has most of its attributes unused and do similar things as CSS inheritance in an incompatible way. As a consequence, it was difficult to implement all MathML features properly in Gecko and this is the source of many bugs like the one I mention in the previous paragraph.

    Hopefully, the new MathML support in Chrome will bring more interest to MathML from contributors or Web companies. Dave told me that Google could hire a full-time engineer to work on MathML. Apparently, this is mostly because of demands from companies working on Webkit-based mobile devices or involved in EPUB. Although I don't have the same impression from Mozilla Corporation at the moment, I'm confident that with the upcoming FirefoxOS release, things might change a bit.

    Finally I also expect that we, at MathJax, will continue to accompany the MathML implementations in browsers. One of the ideas I proposed to the team was to let MathJax select the output mode according to the MathML features supported by the browser. Hence the native MathML support could be used if the page contains only basic mathematics while MathJax's rendering engine will be used when more advanced mathematical constructions are involved. Another goal to achieve will be to make MathJax the default rendering in Wikipedia, which will be much better than the current raster image approach and will allow the users to switch to their browser's MathML support if they wish...

    By fredw at January 11, 2013 12:53 PM

    August 01, 2012

    WebKit CSS3 text-decoration properties (preview)

    Bruno de Oliveira Abinader

    WebKit currently supports CSS Text Level 2.1 version of text-decoration property (link). This version treats only about the decoration line types (underline, overline, line-through and blink – the latter is not supported on WebKit).

    The draft version of CSS Text Level 3 upgrades text-decoration (link) property as a shorthand to 3 newly added properties, named text-decoration-line (link), text-decoration-style (link) and text-decoration-color (link), and also adds text-decoration-skip (link) property.

    Among other WebKit stuff I’ve been doing lately, this feature implementation is one of the most cool ones I’m enjoying implementing. I’ve grabbed the task of implementing all of these CSS3 text-decoration* properties on WebKit, and results are great so far!

    As you can see below, these are the new text decoration styles (solid, double, dotted, dashed and wavy – the latter still requires platform support) available:

    Text decoration style layout test results on Qt platform

    And also specific text decoration colors can be set:

    Text decoration color layout test results on Qt platform

    These features (with exception to text-decoration-skip property) are already implemented on Firefox, thus it gets easier to compare results with different web engines. It is important to notice since CSS3 specification is still in development, all these properties have a -webkit- prefix (ie. -webkit-text-decoration), so text-decoration still maintains CSS2.1 specification requirements. The patches are being reviewed and will soon land upstream, let’s hope it will be soon!

    By Bruno Abinader at August 01, 2012 09:58 PM

    April 11, 2012

    A guide for Qt5/WebKit2 development setup for Nokia N9 on Ubuntu Linux

    Bruno de Oliveira Abinader

    As part of my daily activities at basysKom on QtWebKit maintenance and development for Nokia devices, it is interesting to keep a track on latest developments circa QtWebKit. There is currently a promising project of a Qt5/WebKit2-based browser called Snowshoe mainly developed by my fellow friends from INdT which is completely open-source. This browser requires latest Qt5 and QtWebKit binaries and thus requires us to have a functional build system environment. There is a guide available on WebKit’s wiki (link) which is very helpful but lacks some information about compilation issues found when following the setup steps. So I am basing this guide from that wiki page and I hope that it gets updated soon :)

    On this guide it is assumed the following:

    • All commands are issued on a Linux console. I am not aware of how this guide would work on other systems.
    • All commands are supposed to be issued inside base directory, unless expressely said otherwise (ie. cd <QT5_DIR>).
    • You might want to check if you have git and rsync packages installed in your system.

    1. Install Qt SDK

    In order to build Qt5 and QtWebKit for Nokia N9, you need to set up a cross-compiler. Thankfully, Qt SDK already comes with a working setup. Please download the online installer from Qt Downloads section (link).

    NOTE: The offline installer comes with an outdated version of the MADDE target, which can be updated by running the script below and chosing “Update components” when asked:

    $ ~/QtSDK/SDKMaintenanceTool

    2. Directory setup

    It is suggested (and actually required by some build scripts) to have a base directory which holds Qt5, Qt Components and WebKit project sources. The suggested base directory can be created by running:

    $ mkdir -p ~/swork

    NOTE: You can actually choose another directory name, but so far it is required by some scripts to have at least a symbolic link pointing to <HOME_DIR>/swork.

    3. Download convenience scripts

    3.1. browser-scripts

    $ git clone browser-scripts

    3.2. rsync-scripts

    $ wget
    $ tar xzf rsync-scripts.tar.gz

    4. Download required sources

    4.1. testfonts

    $ git clone git://

    4.2. Qt5, QtComponents and WebKit

    The script below when successfully run will create ~/swork/qt5, ~/swork/qtcomponents and ~/swork/webkit directories:

    $ browser-scripts/ --no-ssh

    NOTE: You can also manually download sources, but remember to stick with the directory names described above.

    5. Pre-build hacks

    5.1. Qt5 translations

    Qt5 translations are not being properly handled by cross-platform toolchain. This happens mainly because lrelease application is called to generate Qt message files, but since it is an ARMEL binary your system is probably not capable of running it natively (unless you have a misc_runner kernel module properly set, then you can safely skip this step). In this case, you can use lrelease from your system’s Qt binaries without any worries.

    If you have a Scratchbox environment set, it is suggested for you to stop its service first:

    $ sudo service scratchbox-core stop

    Now you can manually generate Qt message files by running this:

    $ cd ~/swork/qt5/qttranslations/translations
    $ for file in `ls *ts`; do lrelease $file -qm `echo "$file" | sed 's/ts$/qm/'`; done

    5.2. Disable jsondb-client tool

    QtJsonDB module from Qt5 contains a tool called jsondb-client, which depends on libedit (not available on MADDE target). It is safe to disable its compilation for now:

    $ sed -i 's/jsondb-client//' ~/swork/qt5/qtjsondb/tools/

    5.3. Create missing symbolic links

    Unfortunately Qt5 build system is not robust enough to support our cross-compilation environment, so some symbolic links are required on MADDE to avoid compilation errors (where <USER> is your system user name):

    $ ln -s ~/swork/qt5/qtbase/include ~/QtSDK/Madde/sysroots/harmattan_sysroot_10.2011.34-1_slim/home/<USER>/swork/qt5/qtbase
    $ ln -s ~/swork/qt5/qtbase/mkspecs ~/QtSDK/Madde/sysroots/harmattan_sysroot_10.2011.34-1_slim/home/<USER>/swork/qt5/mkspecs

    6. Build sources

    You can execute the script that will build all sources using cross-compilation setup:

    $ browser-scripts/ --cross-compile

    If everything went well, you now have the most up-to-date binaries for Qt5/WebKit2 development for Nokia N9. Please have a look at WebKit’s wiki for more information about how to update sources after a previous build and information on how to keep files in sync with device. The guide assumes PR1.1 firmware for N9 device, which is already outdated, so I might come up next with updated instructions on how to safely sync files to your PR1.2-enabled device.

    That’s all for now, I appreciate your comments and feedback!

    By Bruno Abinader at April 11, 2012 07:18 AM

    March 10, 2012

    WebKitGTK+ Debian packaging repository changes

    Gustavo Noronha

    For a while now the git repository used for packaging WebKitGTK+ has been broken. Broken as in nobody was able to clone it. In addition to that, the packaging workflow had been changing over time, from a track-upstream-git/patches applied one to a import-orig-only/patches-not-applied one.

    After spending some more time trying to unbreak the repository for the third time I decided it might be a good time for a clean up. I created a new repository, imported all upstream versions for series 1.2.x (which is in squeeze), 1.6.x (unstable), and 1.7.x (experimental). I also imported packaging-related commis for those versions using git format-patch and black magic.

    One of the good things about doing this move, and which should make hacking the WebKitGTK+ debian package more pleasant and accessible can be seen here:

    kov@goiaba ~/s/debian-webkit> du -sh webkit/.git webkit.old/.git
    27M webkit/.git
    1.6G webkit.old/.git

    If you care about the old repository, it’s on still, named old-webkit.git. Enjoy!

    By kov at March 10, 2012 05:32 PM

    December 07, 2011

    WebKitGTK+ hackfest \o/

    Gustavo Noronha

    It’s been a couple days since I returned from this year’s WebKitGTK+ hackfest in A Coruña, Spain. The weather was very nice, not too cold and not too rainy, we had great food, great drinks and I got to meet new people, and hang out with old friends, which is always great!

    Hackfest black board, photo by Mario

    I think this was a very productive hackfest, and as usual a very well organized one! Thanks to the GNOME Foundation for the travel sponsorship, to our friends at Igalia for doing an awesome job at making it happen, and to Collabora for sponsoring it and granting me the time to go there! We got a lot done, and although, as usual, our goals list had many items not crossed, we did cross a few very important ones. I took part in discussions about the new WebKit2 APIs, got to know the new design for GNOME’s Web application, which looks great, discussed about Accelerated Compositing along with Joone, Alex, Nayan and Martin Robinson, hacked libsoup a bit to port the multipart/x-mixed-replace patch I wrote to the awesome gio-based infrastructure Dan Winship is building, and some random misc.

    The biggest chunk of time, though, ended up being devoted to a very uninteresting (to outsiders, at least), but very important task: making it possible to more easily reproduce our test results. TL;DR? We made our bots’ and development builds use jhbuild to automatically install dependencies; if you’re using tarballs, don’t worry, your usual autogen/configure/make/make install have not been touched. Now to the more verbose version!

    The need

    Our three build slaves reporting a few failures

    For a couple years now we have supported an increasingly complex and very demanding automated testing infrastructure. We have three buildbot slaves, one provided by Collabora (which I maintain), and two provided by Igalia (maintained by their WebKitGTK+ folks). Those bots build as many check ins as possible with 3 different configurations: 32 bits release, 64 bits release, and 64 bits debug.

    In addition to those, we have another bot called the EWS, or Early Warning System. There are two of those at this moment: one VM provided by Collabora and my desktop, provided by myself. These bots build every patch uploaded to the bugzilla, and report build failures or passes (you can see the green bubbles). They are very important to our development process because if the patch causes a build failure for our port people can often know that before landing, and try fixes by uploading them to bugzilla instead of doing additional commits. And people are usually very receptive to waiting for EWS output and acting on it, except when they take way too long. You can have an idea of what the life of an EWS bot looks like by looking at the recent status for the WebKitGTK+ bots.

    Maintaining all of those bots is at times a rather daunting task. The tests require a very specific set of packages, fonts, themes and icons to always report the same size for objects in a render. Upgrades, for instance, had to be synchronized, and usually involve generating new baselines for a large number of tests. You can see in these instructions, for instance, how strict the environment requirements are – yes, we need specific versions of fonts, because they often cause layouts to change in size! At one point we had tests fail after a compiler upgrade, which made rounding act a bit different!

    So stability was a very important aspect of maintaining these bots. All of them have the same version of Debian, and most of the packages are pinned to the same version. On the other hand, and in direct contradition to the stability requirement, we often require bleeding edge versions of some libraries we rely on, such as libsoup. Since we started pushing WebKitGTK+ to be libsoup-only, its own progress has been pretty much driven by WebKitGTK+’s requirements, and Dan Winship has made it possible to make our soup backend much, much simpler and way more featureful. That meant, though, requiring very recent versions of soup.

    To top it off, for anyone not running Debian testing and tracking the exact same versions of packages as the bots it was virtually impossible to get the tests to pass, which made it very difficult for even ourselves to make sure all patches were still passing before committing something. Wow, what a mess.

    The explosion^Wsolution

    So a few weeks back Martin Robinson came up with a proposed solution, which, as he says, is the “nuclear bomb” solution. We would have a jhbuild environment which would build and install all of the dependencies necessary for reproducing the test expectations the bots have. So over the first three days of the hackfest Martin and myself hacked away in building scripts, buildmaster integration, a jhbuild configuration, a jhbuild modules file, setting up tarballs, and wiring it all in a way that makes it convenient for the contributors to get along with. You’ll notice that our buildslaves now have a step just before compiling called “updated gtk dependencies” (gtk is the name we use for our port in the context of WebKit), which runs jhbuild to install any new dependencies or version bumps we added. You can also see that those instructions I mentioned above became a tad simpler.

    It took us way more time than we thought for the dust to settle, but it eventually began to. The great thing of doing it during the hackfest was that we could find and fix issues with weird configurations on the spot! Oh, you build with AR_FLAGS=cruT and something doesn’t like it? OK, we fix it so that the jhbuild modules are not affected by that variable. Oh, turns out we missed a dependency, no problem, we add it to the modules file or install them on the bots, and then document the dependency. I set up a very clean chroot which we could use for trying out changes so as to not disrupt the tree too much for the other hackfest participants, and I think overall we did good.

    The aftermath

    By the time we were done our colleagues who ran other distributions such as Fedora were already being able to get a substantial improvements to the number of tests passing, and so did we! Also, the ability to seamlessly upgrade all the bots with a simple commit made it possible for us to very easily land a change that required a very recent (as in unreleased) version of soup which made our networking backend way simpler. All that red looks great, doesn’t it? And we aren’t done yet, we’ll certainly be making more tweaks to this infrastructure to make it more transparent and more helpful to the users (contributors and other people interested in running the tests).

    If you’ve been hit by the instability we caused, sorry about that, poke mrobinson or myself in the #webkitgtk+ IRC channel on FreeNode, and we’ll help you out or fix any issues. If you haven’t, we hope you enjoy all the goodness that a reproducible testing suite has to offer! That’s it for now, folks, I’ll have more to report on follow-up work started at the hackfest soon enough, hopefully =).

    By kov at December 07, 2011 11:34 PM

    November 29, 2011

    Accelerated Compositing in webkit-clutter

    Gustavo Noronha

    For a while now my fellow Collaboran Joone Hur has been working on implementing the Accelerated Compositing infrastructure available in WebKit in webkit-clutter, so that we can use Clutter’s powers for compositing separate layers and perform animations. This work is being done by Collabora and is sponsored by BOSCH, whom I’d like to thank! What does all this mean, you ask? Let me tell me a bit about it.

    The way animations usually work in WebKit is by repainting parts of the page every few milliseconds. What that means in technical terms is that an area of the page gets invalidated, and since the whole page is one big image, all of the pieces that are in that part of the page have to be repainted: the background, any divs, images, text that are at that part of the page.

    What the accelerated compositing code paths allow is the creation of separate pieces to represent some of the layers, allowing the composition to happen on the GPU, removing the need to perform lots of cairo paint operations per second in many cases. So if we have a semi-transparent video moving around the page, we can have that video be a separate texture that is layered on top of the page, made transparent and animated by the GPU. In webkit-clutter’s case this is done by having separate actors for each of the layers.

    I have been looking at this code on and off, and recently joined Joone in the implementation of some of the pieces. The accelerated compositing infrastructure was originally built by Apple and is, for that reason, works in a way that is very similar to Core Animation. The code is still a bit over the place as we work on figuring out how to best translate the concepts into clutter concepts and there are several bugs, but some cool demos are already possible! Bellow you have one of the CSS3 demos that were made by Apple to demo this new functionality running on our MxLauncher test browser.

    You can also see that the non-Accelerated version is unable to represent the 3D space correctly. Also, can you guess which of the two MxLauncher instances is spending less CPU? ;) In this second video I show the debug borders being painted around the actors that were created to represent layers.

    The code, should you like to peek or test is available in the ac2 branch of our webkit-clutter repository:

    We still have plenty of work to do, so expect to hear more about it. During our annual hackfest in A Coruña we plan to discuss how this work could be integrated also in the WebKitGTK+ port, perhaps by taking advantage of clutter-gtk, which would benefit both ports, by sharing code and maintenance, and providing this great functionality to Epiphany users. Stay tuned!

    By kov at November 29, 2011 05:55 PM

    October 09, 2011

    Tests Active

    Brent Fulgham

    Looking back over this blog, I see that it was around a year ago that I got the initial WinCairo buildbot running. I'm very pleased to announce that I have gotten ahold of a much more powerful machine, and am now able to run a full build and tests in slightly under an hour -- a huge improvement over the old hardware which took over two hours just to build the software!

    This is a big step, because we can now track regressions and gauge correctness compared to the other platforms. Up to now, testing has largely consisted of periodic manual runs of the test suite, and a separate set of high-level tests run as part of a larger application. This was not ideal, because it was easy for low-level functions in WebKit that I rarely use to be broken and missed.

    All is not perfect, of course. Although over 12,000 tests now run (successfully) with each build, that is effectively two thirds of the full test suite. Most of the tests I have disabled are due to small differences in the output layout. I'm trying to understand why these differences exist, but I suspect many of them simply reflect small differences in Cairo compared to the CoreGraphics rendering layer.

    If any of you lurkers are interested in helping out, trying out some of the tests I have disabled and figuring out why they fail would be a huge help!

    By Brent Fulgham ( at October 09, 2011 02:43 AM

    July 14, 2011

    An Unseasonable Snowfall

    Brent Fulgham

    A year or two ago I ported the Cocoa "CallJS" application to MFC for use with WebKit. The only feedback I ever got on the topic was a complaint that it would not build under the Visual Studio Express software many people used.

    After seeing another few requests on the webkit-help mailing list for information on calling JavaScript from C++ (and vice-versa), I decided to dust off the old program and convert it to pure WINAPI calls so that VS Express would work with it.

    Since my beloved Layered Window patches finally landed in WebKit, I also incorporated a transparent WebKit view floating over the main application window. Because I suck at art, I stole appropriated the Let It Snow animation example to give the transparent layer something to do.

    Want to see what it looks like?

    By Brent Fulgham ( at July 14, 2011 06:34 PM

    July 10, 2011

    Updated WebKit SDK (@r89864)

    Brent Fulgham

    I have updated the WebKitSDK to correspond to SVN revision r8984.

    Major changes in this revision:
    * JavaScript engine improvements.
    * Rendering improvements.
    * New 'Transparent Web View' support.
    * General performance and memory use improvements.

    This ZIP file also contains updated versions of Zlib, OpenSSL, cURL, and OpenCFLite.

    Note that I have stopped statically linking Cairo; I'm starting to integrate some more recent Cairo updates (working towards some new rendering features), and wanted to be able to update it incrementally as changes are made.

    This package contains the same Cairo library (in DLL form) as used in previous versions.

    As usual, please let me know if you encounter any problems with this build.

    [Update] I forgot to include zlib1.dll! Fixed in the revised zip file.

    By Brent Fulgham ( at July 10, 2011 04:24 AM

    July 05, 2011

    WinCairoRequirements Sources Archive

    Brent Fulgham

    I've posted the 80 MB source archive of the requirements needed to build the WinCairo port of WebKit.

    Note that you do NOT need these sources unless you plan on building them yourself or wish to archive the source code for these modules. The binaries are always present in the file, which is downloaded and unzipped to the proper place when you execute the update-webkit --wincairo command.

    By Brent Fulgham ( at July 05, 2011 07:39 PM

    June 28, 2011

    Towards a Simpler WinCairo Build

    Brent Fulgham

    For the past couple of years, anyone interested in trying to build the WinCairo port of WebKit had to track down a number of support libraries, place them in their development environment's include (and link search) paths, and then cross their fingers and hope everything built.

    To make things a little easier, I wrapped up the libraries and headers I use for building and posted them as a zip file on my .Mac account. This made things a little easier, but you still had to figure out where to drop the files and figure out if I had secretly updated my '' file without telling anyone. Not ideal.

    A couple of days ago, while trolling through the open review queue, I ran across a Bug filed by Carl Lobo, which automated the task of downloading the requirements file when running build-webkit --wincairo. This was a huge improvement!

    Today, I hijacked Carl's changes and railroaded the patch through the review process (making a few modifications along the way):

    • I renamed my requirements file

    • I added a timestamp file, so that build-webkit --wincairo can check to see if the file changed, and download it if necessary.

    • I propagated Carl's changes to update-webkit, so that now by adding the --wincairo argument it will update the WinCairoRequirements file.

    I'm really excited about this update. If you've been wanting to try out the WinCairo port of WebKit, this would be a great time to try it out. I'd love to hear your experiences!

    By Brent Fulgham ( at June 28, 2011 04:42 AM

    June 14, 2011

    Benchmarking Javascript engines for EFL

    Lucas De Marchi

    The Enlightenment Foundation Libraries has several bindings for other languages in order to ease the creation of end-user applications, speeding up its development. Among them, there’s a binding for Javascript using the Spidermonkey engine. The questions are: is it fast enough? Does it slowdown your application? Is Spidermonkey the best JS engine to be used?

    To answer these questions Gustavo Barbieri created some C, JS and Python benchmarks to compare the performance of EFL using each of these languages. The JS benchmarks were using Spidermonkey as the engine since elixir was already done for EFL. I then created new engines (with only the necessary functions) to also compare to other well-known JS engines: V8 from Google and JSC (or nitro) from WebKit.

    Libraries setup

    For all benchmarks EFL revision 58186 was used. Following the setup of each engine:

    • Spidermonkey: I’ve used version 1.8.1-rc1 with the already available bindings on EFL repository, elixir;
    • V8: version, using a simple binding I created for EFL. I named this binding ev8;
    • JSC: WebKit’s sources are needed to compile JSC. I’ve used revision 83063. Compiling with CMake, I chose the EFL port and enabled the option SHARED_CORE in order to have a separated library for Javascript;


    Startup time: This benchmark measures the startup time by executing a simple application that imports evas, ecore, ecore-evas and edje, bring in some symbols and then iterates the main loop once before exiting. I measured the startup time for both hot and cold cache cases. In the former the application is executed several times in sequence and the latter includes a call to drop all caches so we have to load the library again from disk

    Runtime – Stress: This benchmark executes as many frames per second as possible of a render-intensive operation. The application is not so heavy, but it does some loops, math and interacts with EFL. Usually a common application would do far less operations every frame because many operations are done in EFL itself, in C, such as list scrolling that is done entirely in elm_genlist. This benchmark is made of 4 phases:

    • Phase 0 (P0): Un-scaled blend of the same image 16 times;
    • Phase 1 (P1): Same as P0, with additional 50% alpha;
    • Phase 2 (P2): Same as P0, with additional red coloring;
    • Phase 3 (P3): Same as P0, with additional 50% alpha and red coloring;

    The C and Elixir’s versions are available at EFL repository.

    Runtime – animation: usually an application doesn’t need “as many FPS as possible”, but instead it would like to limit to a certain amount of frames per second. E.g.: iphone’s browser tries to keep a constant of 60 FPS. This is the value I used on this benchmark. The same application as the previous benchmark is executed, but it tries to keep always the same frame-rate.


    The first computer I used to test these benchmarks on was my laptop. It’s a Dell Vostro 1320, Intel Core 2 Duo with 4 GB of RAM and a standard 5400 RPM disk. The results are below.

    Benchmarks on Dell 1320 laptop

    First thing to notice is there are no results for “Runtime – animation” benchmark. This is because all the engines kept a constant of 60fps and hence there were no interesting results to show. The first benchmark shows that V8’s startup time is the shortest one when considering we have to load the application and libraries from disk. JSC was the slowest and  Spidermonkey was in between.

    With hot caches, however, we have another complete different scenario, with JSC being almost as fast as the native C application. Following, V8 with a delay a bit larger and Spidermonkey as the slowest one.

    The runtime-stress benchmark shows that all the engines are performing well when there’s some considerable load in the application, i.e. removing P0 from from this scenario. JSC was always at the same speed of native code; Spidermonkey and V8 had an impact only when considering P0 alone.


    Next computer to consider in order to execute these benchmarks was  a Pandaboard, so we can see how well the engines are performing in an embedded platform. Pandaboard has an ARM Cortex-A9 processor with 1GB of RAM and the partition containing the benchmarks is in an external flash storage drive. Following the results for each benchmark:


    Benchmarks on Pandaboard

    Once again, runtime-animation is not shown since it had the same results for all engines. For the startup tests, now Spidermonkey was much faster than the others, followed by V8 and JSC in both hot and cold caches. In runtime-stress benchmark, all the engines performed well, as in the first computer, but now JSC was the clear winner.


    There are several points to be considered when choosing an engine to be use as a binding for a library such as EFL. The raw performance and startup time seems to be very near to the ones achieved with native code. Recently there were some discussions in EFL mailing list regarding which engine to choose, so I think it would be good to share these numbers above. It’s also important to notice that these bindings have a similar approach of elixir, mapping each function call in Javascript to the correspondent native function. I made this to be fair in the comparison among them, but depending on the use-case it’d  be good to have a JS binding similar to what python’s did, embedding the function call in real python objects.

    By Lucas De Marchi at June 14, 2011 05:25 PM

    April 29, 2011

    Collection of WebKit ports

    Holger Freyther

    WebKit is a very successfull project. It is that in many ways. The code produced seems to very fast, the code is nice to work on, the people are great, the partys involved collaborate with each other in the interest of the project. The project is also very successfull in the mobile/smartphone space. All the major smartphone platforms but Windows7 are using WebKit. This all looks great, a big success but there is one thing that stands out.

    From all the smartphone platforms no one has fully upstreamed their port. There might be many reasons for that and I think the most commonly heard reason is the time needed to get it upstreamed. It is specially difficult in a field that is moving as fast as the mobile industry. And then again there is absolutely no legal obligation to work upstream.

    For most of today I collected the ports I am aware of, put them into one git repository, maybe find the point where they were branched, rebase their changes. The goal is to make it more easy to find interesting things and move them back to upstream. One can find the combined git tree with the tags here. I started with WebOS, moved to iOS, then to Bada and stopped at Android as I would have to pick the sourcecode for each android release for each phone from each vendor. I think I will just be happy with the Android git tree for now. At this point I would like to share some of my observations in the order I did the import.


    Palm's release process is manual. In the last two releases they call the file .tgz but forgot to gzip it, in 2.0.0 the tarball name was in camel case. The thing that is very nice about Palm is that they provide their base and their changes (patch) separately. From looking at the 2.1.0 release it looks that for the Desktop version they want to implement Complex Font rendering. Earlier versions (maybe it is still the case) lack the support for animated GIF.


    Apple's release process seems to be very structured. The source can be downloaded here. What I think is to note is that the release tarball contains some implementations of WebCore only as .o file and Apple has stopped releasing the WebKit sourcecode beginning with iOS 4.3.0.


    This port is probably not known by many. The release process seems to be manual as well, the name of directories changed a lot between the releases, they come with a WML Script engine and they do ship something they should not ship.

    I really hope that this combined tree is useful for porters that want to see the tricks used in the various ports and don't want to spend the time looking for each port separately.

    By zecke ( at April 29, 2011 07:20 PM

    February 13, 2011

    How to make the GNU Smalltalk Interpreter slower

    Holger Freyther

    This is another post about a modern Linux based performance measurement utility. It is called perf, it is included in the Linux kernel sources and it entered the kernel in v2.6.31-rc1. In many ways it is obsoleting OProfile, in fact for many architectures oprofile is just a wrapper around the perf support in the kernel. perf comes with a few nice application. perf top provides a statistics about which symbols in user and in kernel space are called, perf record to record an application or to start an application to record it and then perf report to browse this report with a very simple CLI utility. There are tools to bundle the record and the application in an archive, a diff utility.

    For the last year I was playing a lot with GNU Smalltalk and someone posted the results of a very simplistic VM benchmark ran across many different Smalltalk implementations. In one of the benchmarks GNU Smalltalk is scoring last among the interpreters and I wanted to understand why it is slower. In many cases the JavaScriptCore interpreter is a lot like the GNU Smalltalk one, a simple direct-threaded bytecode interpreter, uses computed goto (even is compiled with -fno-gcse as indicated by the online help, not that it changed something for JSC), heavily inlined many functions.

    There are also some differences, the GNU Smalltalk implementation is a lot older and in C. The first notable is that it is a Stack Machine and not register based, there are global pointers for the SP and the IP. Some magic to make sure that in the hot loop the IP/SP is 'local' in a register, depending on the available registers also keep the current argument in one, the interpreter definition is in a special file format but mostly similar to how Interepreter::privateExecute is looking like. The global state mostly comes from the fact that it needs to support switching processes and there might be some event during the run that requires access to the IP to store it to resume the old process. But in general the implementation is already optimized and there is little low hanging fruits and most experiments result in a slow down.

    The two important things are again: Having a stable benchmark, having a tool to help to know where to look for things. In my case the important tools are perf stat, perf record, perf report and perf annotate. I have put a copy of the output to the end of this blog post. The stat utility provides one with number of instructions executed, branches, branch misses (e.g. badly predicted), L1/L2 cache hits and cache misses.

    The stable benchmark helps me to judge if a change is good, bad or neutral for performance within the margin of error of the test. E.g. if I attempt to reduce the code size the instructions executed should decrease, if I start putting __builtin_expect.. into my code the number of branch misses should go down as well. The other useful utility is to the perf report that allows one to browse the recorded data, this can help to identify the methods one wants to start to optimize, it allows to annotate these functions inside the simple TUI interface, but does not support searching in it.

    Because the codebase is already highly optimized any of my attempts should either decrease the code size (and the pressure on the i-cache), the data size (d-cache), remove stores or loads from memory (e.g. reorder instructions), fix branch predictions. The sad truth is that most of my changes were either slow downs or neutral to the performance and it is really important to undo these changes and not have false pride (unless it was also a code cleanup or such).

    So after about 14 hours of toying with it the speed ups I have managed to make come from inlining a method to unwind a context (callframe), reordering some compares on the GC path and disabling the __builtin_expect branch hints as they were mostly wrong (something the kernel people found to be true in 2010 as well). I will just try harder, or try to work on the optimizer or attempt something more radical...

    $ perf stat gst -f
    219037433 bytecodes/sec; 6025895 sends/sec

    Performance counter stats for 'gst -f':

    17280.101683 task-clock-msecs # 0.969 CPUs
    2076 context-switches # 0.000 M/sec
    123 CPU-migrations # 0.000 M/sec
    3925 page-faults # 0.000 M/sec
    22215005506 cycles # 1285.583 M/sec (scaled from 70.02%)
    40593277297 instructions # 1.827 IPC (scaled from 80.00%)
    5063469832 branches # 293.023 M/sec (scaled from 79.98%)
    70691940 branch-misses # 1.396 % (scaled from 79.98%)
    27844326 cache-references # 1.611 M/sec (scaled from 20.02%)
    134229 cache-misses # 0.008 M/sec (scaled from 20.03%)

    17.838888599 seconds time elapsed

    PS: The perf support probably works best on Intel based platforms and the biggest other problem is that perf annotate has some issues when the code is included from other c files.

    By zecke ( at February 13, 2011 08:56 PM

    January 17, 2011

    Using systemtap userspace tracing...

    Holger Freyther

    At the 27C3 we were running a GSM network and during the preparation I noticed a strange performance problem coming from the database library we are using running. I filled our database with some dummy data and created a file with the queries we normally run and executed time cat queries | sqlite3 file as a mini benchmark. I also hacked this code into our main routine and ran it with time as well. For some reason the code running through the database library was five times slower.

    I was a bit puzzled and I decided to use systemtap to explore this to build a hypothesis and to also have the tools to answer the hypothesis. I wanted to find out if if it is slow because our database library is doing some heavy work in the implementation, or because we execute a lot more queries behind the back. I was creating the below probe:

    probe process("/usr/lib/").function("sqlite3_get_table")
    a = user_string($zSql);
    printf("sqlite3_get_table called '%s'\n", a);

    This probe will be executed whenever the sqlite3_get_table function of the mentioned library will be called. The $zSql is a variable passed to the sqlite3_get_table function and contains the query to be executed. I am converting the pointer to a local variable and then can print it. Using this simple probe helped me to see which queries were executed by the database library and helped me to do an easy optimisation.

    In general it could be very useful to build a set of probes (I think one calls set a tapset) that check for API misusage, e.g. calling functions with certain parameters where something else might be better. E.g. in Glib use truncate instead of assigning "" to the GString, or check for calls to QString::fromUtf16 coming from Qt code itself. On second thought this might be better as a GCC plugin, or both.

    By zecke ( at January 17, 2011 12:41 PM

    December 17, 2010

    In the name of performance

    Holger Freyther

    I tend to see people doing weird things and then claim that the change is improving performance. This can be re-ordering instructions to help the compiler, attempting to use multiple cores of your system, writing a memfill in assembly. On the one hand people can be right and the change is making things faster, on the other hand they could use assembly to make things look very complicated, justify their pay, and you might feel awkward to question if it is making any sense.

    In the last couple of weeks I have stumbled on some of those things. For some reason I found this bug report about GLIBC changing the memcpy routine for SSE and breaking the flash plugin (because it uses memcpy in the wrong way). The breakage is justified that the new memcpy was optimized and is faster. As Linus points out with his benchmark the performance improvement is mostly just wishful thinking.

    Another case was someone providing MIPS optimized pixman code to speed-up all drawing which turned out to be wishful thinking as well...

    The conclusion is. If someone claims that things are faster with his patch. Do not simply trust him, make sure he refers to his benchmark, is providing numbers of before and after and maybe even try to run it yourself. If he can not provide this, you should wonder how he measured the speed-up! There should be no place for wishful thinking in benchmarking. This is one of the areas where Apple's WebKit team is constantly impressing me.

    By zecke ( at December 17, 2010 01:48 PM

    December 16, 2010

    Benchmarking QtWebKit-V8 on Linux

    University of Szeged

    For some time it has been possible to build and run QtWebKit on Linux using Google's V8 JavaScript engine instead of the default JavaScriptCore. I thought it would be good to see some numbers comparing the runtime performance of the two engines in the same environment and also measuring the performance of the browser bindings.

    read more

    By andras.becsi at December 16, 2010 01:04 PM

    October 23, 2010

    Easily embedding WebKit into your EFL application

    Lucas De Marchi

    This is the first of a series of posts that I’m planning to do using basic examples in EFL, the Enlightenment Foundation Libraries. You may have heard that EFL is reaching its 1.0 release. Instead of starting from the very beginning with the basic functions of these libraries, I decided to go the opposite way, showing the fun stuff that is possible to do. Since I’m also an WebKit developer, let’s put the best of both softwares together and have a basic window rendering a webpage.

    Before starting off, just some remarks:

    1. I’m using here the basic EFL + WebKit-EFL (sometimes called ewebkit). Developing an EFL application can be much simpler, particularly if you use an additional library with pre-made widgets like Elementary. However, it’s good to know how the underlying stuff works, so I’m providing this example.
    2. This could have been the last post in a series when talking about EFL since it uses at least 3 libraries. Don’t be afraid if you don’t understand what a certain function is for or if you can’t get all EFL and WebKit running right now. Use the comment section below and I’ll make my best to help you.

    Getting EFL and WebKit

    In order to able to compile the example here, you will need to compile two libraries from source: EFL and WebKit. For both libraries, you can either get the last version from svn or use the last snapshots provided.

    • EFL:

    Grab a snapshot from the download page. How to checkout the latest version from svn is detailed here, as well as some instructions on how to compile

    • WebKit-EFL:

    A very detailed explanation on how to get WebKit-EFL up and running is available on trac. Recently, though, WebKit-EFL started to be released too. It’s not detailed in the wiki yet, but you can grab a snapshot instead of checking out from svn.


    In the spirit of “hello world” examples, our goal here is to make a window showing a webpage rendered by WebKit. For the sake of simplicity, we will use a default start page and put a WebKit-EFL “widget” to cover the entire window. See below a screenshot:

    hellobrowser - WebKit + EFL

    The code for this example is available here. Pay attention to a comment in the beginning of this file that explains how to compile it:

    gcc -o hellobrowser hellobrowser.c \
         -DEWK_DATADIR="\"$(pkg-config --variable=datadir ewebkit)\"" \
         $(pkg-config --cflags --libs ecore ecore-evas evas ewebkit)

    The things worth noting here are the dependencies and a variable. We directly depend on ecore and evas from EFL and on WebKit. We define a variable, EWK_DATADIR, using pkg-config so our browser can use the default theme for web widgets defined in WebKit. Ecore handles events like mouse and keyboard inputs, timers etc whilst evas is the library responsible for drawing. In a later post I’ll detail them a bit more. For now, you can read more about them on their official site.

    The main function is really simple. Let’s divide it by pieces:

        // Init all EFL stuff we use

    Before you use a library from EFL, remember to initialize it. All of them use their own namespace, so it’s easy to know which library you have to initialize: for example, if you call a function starting by “ecore_”, you know you first have to call “ecore_init()”. The last initialization function is WebKit’s, which uses the “ewk_” namespace.

        window = ecore_evas_new(NULL, 0, 0, 800, 600, NULL);
        if (!window) {
            fprintf(stderr, "something went wrong... :(\n");
            return 1;

    Ecore-evas then is used to create a new window with size 800×600. The other options are not relevant for an introduction to the libraries and you can find its complete documentation here.

        // Get the canvas off just-created window
        evas = ecore_evas_get(window);

    From the Ecore_Evas object we just created, we grab a pointer to the evas, which is the space in which we can draw, adding Evas_Objects. Basically an Evas_Object is an object that you draw somewhere, i.e. in the evas. We want to add only one object to our window, that is where WebKit you render the webpages. Then, we have to ask WebKit to create this object:

        // Add a View object into this canvas. A View object is where WebKit will
        // render stuff.
        browser = ewk_view_single_add(evas);

    Below I demonstrate a few Evas’ functions that you use to manipulate any Evas_Object. Here we are manipulating the just create WebKit object, moving to the desired position, resizing to 780x580px and then telling Evas to show this object. Finally, we tell Evas to show the window we created too. This way we have a window with an WebKit object inside with a little border.

        // Make a 10px border, resize and show
        evas_object_move(browser, 10, 10);
        evas_object_resize(browser, 780, 580);

    We need to setup a bit more things before having a working application. The first one is to give focus to the Evas_Object we are interested on in order to receive keyboard events when opened. Then we connect a function that will be called when the window is closed, so we can properly exit our application.

        // Focus it so it will receive pressed keys
        evas_object_focus_set(browser, 1);
        // Add a callback so clicks on "X" on top of window will call
        // main_signal_exit() function
        ecore_event_handler_add(ECORE_EVENT_SIGNAL_EXIT, main_signal_exit, window);

    After this, we are ready to show our application, so we start the mainloop. This function will only return when the application is closed:


    The function called when the application is close, just tell Ecore to exit the mainloop, so the function above returns and the application can shutdown. See its implementation below:

    static Eina_Bool
    main_signal_exit(void *data, int ev_type, void *ev)
        return EINA_TRUE;

    Before the application exits, we shutdown all the libraries that were initialized, in the opposite order:

        // Destroy all the stuff we have used

    This is a basic working browser, with which you can navigate through pages, but you don’t have an entry to set the current URL, nor “go back” and “go forward” buttons etc. All you have to do is start adding more Evas_Objects to your Evas and connect them to the object we just created. For a still basic example, but with more stuff implemented, refer to the EWebLauncher that we ship with the WebKit source code. You can see it in the “WebKitTools/EWebLauncher/” folder or online at webkit’s trac. Eve is another browser with a lot more features that uses Elementary in addition to EFL, WebKit. See a blog post about it with some nice pictures.

    Now, let’s do something funny with our browser. With a bit more lines of code you can turn your browser upside down. Not really useful, but it’s funny. All you have to do is to rotate the Evas_Object WebKit is rendering on. This is implemented by the following function:

    // Rotate an evas object by 180 degrees
    static void
    _rotate_obj(Evas_Object *obj)
        Evas_Map *map = evas_map_new(4);
        evas_map_util_points_populate_from_object(map, obj);
        evas_map_util_rotate(map, 180.0, 400, 300);
        evas_map_alpha_set(map, 0);
        evas_map_smooth_set(map, 1);
        evas_object_map_set(obj, map);
        evas_object_map_enable_set(obj, 1);

    See this screenshot below and  get the complete source code.

    EFL + WebKit doing Politreco upside down

    By Lucas De Marchi at October 23, 2010 09:53 PM

    October 02, 2010

    Deploying WebKit, common issues

    Holger Freyther

    From my exposure to people deploying QtWebKit or WebKit/GTK+ there are some things that re-appear and I would like to discuss these here.

    • Weird compile error in JavaScript?
    • It is failing in JavaScriptCore as it is the first that is built. It is most likely that the person that provided you with the toolchain has placed a config.h into it. There are some resolutions to it. One would be to remove the config.h from the toolchain (many things will break), or use -isystem instead of -I for system includes.
      The best way to find out if you suffer from this problem is to use -E instead of -c to only pre-process the code and see where the various includes are coming from. It is a strategy that is known to work very well.

    • No pages are loaded.
    • Most likely you do not have a DNS Server set, or no networking, or the system your board is connected to is not forwarding the data. Make sure you can ping a website that is supposed to work, e.g. ping, the next thing would be to use nc to execute a simple HTTP 1.1 get on the site and see if it is working. In most cases you simply lack networking connectivity.

    • HTTPS does not work
    • It might be either an issue with Qt or an issue with your system time. SSL Certificates at least have two dates (Expiration and Creation) and if your system time is after the Expiration or before the Creation you will have issues. The easiest thing is to add ntpd to your root filesystem to make sure to have the right time.

      The possible issue with Qt is a bit more complex. You can build Qt without OpenSSL support, you can make it link to OpenSSL or you can make it to dlopen OpenSSL at runtime. If SSL does not work it is most likely that you have either build it without SSL support, or with runtime support but have failed to install the OpenSSL library.

      Depending on your skills it might be best to go back to ./configure and make Qt link to OpenSSL to avoid the runtime issue. strings is a very good tool to find out if your contains SSL support, together with using objdump -x and search for _NEEDED you will find out which config you have.

    • Local pages are not loaded
    • This is a pretty common issue for WebKit/GTK+. In WebKit/GTK+ we are using GIO for local files and to determine the filetype it is using the shared-mime-info. Make sure you have that installed.

    • The page only displays blank
    • This is another issue that comes back from time to time. It only appears on WebKit/GTK+ with the DirectFB backend but sadly people never report back if and how they have solved it. You could make a difference and contribute back to the WebKit project.

      In general most of these issues can be avoided by using a pre-packaged Embedded Linux Distribution like Ångström (or even Debian). The biggest benefit of that approach is that someone else made sure that when you install WebKit, all dependencies will be installed as well and it will just work for your ARM/MIPS/PPC system. It will save you a lot of time.

      By zecke ( at October 02, 2010 06:12 AM

      August 28, 2010


      Lucas De Marchi

      After some time working with the EFL port of WebKit, I’ve been nominated as an official webkit developer. Now I have super powers in the official repository :-), but I swear I intend to use it with caution and responsibility. I’ll not forget Uncle Ben’s advice: ”with great power comes great responsibility”.

      I’m preparing a post to talk about WebKit, EFL, eve (a new web browser based on WebKit + EFL) and how to easily embed a browser in your application. Stay tuned.

      By Lucas De Marchi at August 28, 2010 03:15 AM

      August 10, 2010

      Coscup2010/GNOME.Asia with strong web focus

      Holger Freyther

      On the following weekend the Coscup 2010/GNOME.Asia is taking place in Taipei. The organizers have decided to have a strong focus on the Web as can be seen in the program.

      On saturday there are is a keynote and various talks about HTML5, node.js. The Sunday will see three talks touching WebKit/GTK+. There is one about building a tablet OS with WebKit/GTK+, one by Xan Lopez on how to build hybrid applications (a topic I have devoted to) and a talk by me using gdb to explain how WebKit/GTK+ is working and how the porting layer interacts with the rest of the code.

      I hope the audience will enjoy the presentations and I am looking forward to attend the conference, there is also a strong presence of the ex-Openmoko Taiwan Engineering team. See you on Saturday/Sunday and drop me an email if you want to talk about WebKit or GSM...

      By zecke ( at August 10, 2010 04:32 PM

      July 16, 2010

      Cross-compiling QtWebKit for Windows on Linux using MinGW

      University of Szeged

      In this post I'll show you how to configure and compile a MinGW toolchain for cross-compilation on Linux, then how to build Qt using this toolchain and finally compile the Qt port of WebKit from trunk.

      read more

      By andras.becsi at July 16, 2010 09:31 AM

      September 06, 2008

      Skia graphics library in Chrome: First impressions

      Alp Toker

      With the release of the WebKit-based Chrome browser, Google also introduced a handful of new backends for the browser engine including a new HTTP stack and the Skia graphics library. Google’s Android WebKit code drops have previously featured Skia for rendering, though this is the first time the sources have been made freely available. The code is apparently derived from Google’s 2005 acquisition of North Carolina-based software firm Skia and is now provided under the Open Source Apache License 2.0.

      Weighing in at some 80,000 lines of code (to Cairo’s 90,000 as a ballpark reference) and written in C++, some of the differentiating features include:

      • Optimised software-based rasteriser (module sgl/)
      • Optional GL-based acceleration of certain graphics operations including shader support and textures (module gl/)
      • Animation capabilities (module animator/)
      • Some built-in SVG support (module (svg/)
      • Built-in image decoders: PNG, JPEG, GIF, BMP, WBMP, ICO (modules images/)
      • Text capabilities (no built-in support for complex scripts)
      • Some awareness of higher-level UI toolkit constructs (platform windows, platform events): Mac, Unix (sic. X11, incomplete), Windows, wxwidgets
      • Performace features
        • Copy-on-write for images and certain other data types
        • Extensive use of the stack, both internally and for API consumers to avoid needless allocations and memory fragmentation
        • Thread-safety to enable parallelisation

      The library is portable and has (optional) platform-specific backends:

      • Fonts: Android / Ascender, FreeType, Windows (GDI)
      • Threading: pthread, Windows
      • XML: expat, tinyxml
      • Android shared memory (ashmem) for inter-process image data references

      Skia Hello World

      In this simple example we draw a few rectangles to a memory-based image buffer. This also demonstrates how one might integrate with the platform graphics system to get something on screen, though in this case we’re using Cairo to save the resulting image to disk:

      #include "SkBitmap.h"
      #include "SkDevice.h"
      #include "SkPaint.h"
      #include "SkRect.h"
      #include <cairo.h>
      int main()
        SkBitmap bitmap;
        bitmap.setConfig(SkBitmap::kARGB_8888_Config, 100, 100);
        SkDevice device(bitmap);
        SkCanvas canvas(&device);
        SkPaint paint;
        SkRect r;
        paint.setARGB(255, 255, 255, 255);
        r.set(10, 10, 20, 20);
        canvas.drawRect(r, paint);
        paint.setARGB(255, 255, 0, 0);
        r.offset(5, 5);
        canvas.drawRect(r, paint);
        paint.setARGB(255, 0, 0, 255);
        r.offset(5, 5);
        canvas.drawRect(r, paint);
          SkAutoLockPixels image_lock(bitmap);
          cairo_surface_t* surface = cairo_image_surface_create_for_data(
              (unsigned char*)bitmap.getPixels(), CAIRO_FORMAT_ARGB32,
              bitmap.width(), bitmap.height(), bitmap.rowBytes());
          cairo_surface_write_to_png(surface, "snapshot.png");
        return 0;

      You can build this example for yourself linking statically to the libskia.a object file generated during the Chrome build process on Linux.

      Not just for Google Chrome

      The Skia backend in WebKit, the first parts of which are already hitting SVN (r35852, r36074) isn’t limited to use in the Chrome/Windows configuration and some work has already been done to get it up and running on Linux/GTK+ as part of the ongoing porting effort.

      The post Skia graphics library in Chrome: First impressions appeared first on Alp Toker.

      By alp at September 06, 2008 12:11 AM

      June 12, 2008

      WebKit Meta: A new standard for in-game web content

      Alp Toker

      Over the last few months, our browser team at Nuanti Ltd. has been developing Meta, a brand new WebKit port suited to embedding in OpenGL and 3D applications. The work is being driven by Linden Lab, who are eagerly investigating WebKit for use in Second Life.

      While producing Meta we’ve paid great attention to resolving the technical and practical limitations encountered with other web content engines.

      uBrowser running with the WebKit Meta engine

      High performance, low resource usage

      Meta is built around WebKit, the same engine used in web browsers like Safari and Epiphany, and features some of the fastest content rendering around as well as nippy JavaScript execution with the state of the art SquirrelFish VM. The JavaScript SDK is available independently of the web renderer for sandboxed client-side game scripting and automation.

      It’s also highly scalable. Some applications may need only a single browser context but virtual worlds often need to support hundreds of web views or more, each with active content. To optimize for this use case, we’ve cut down resource usage to an absolute minimum and tuned performance across the board.

      Stable, easy to use cross-platform SDK

      Meta features a single, rock-solid API that works identically on all supported platforms including Windows, OS X and Linux. The SDK is tailored specifically to embedding and allows tight integration (shared main loop or operation in a separate rendering thread, for example) and hooks to permit seamless visual integration and extension. There is no global setup or initialization and the number of views can be adjusted dynamically to meet resource constraints.

      Minimal dependencies

      Meta doesn’t need to use a conventional UI toolkit and doesn’t need any access to the underlying windowing system or the user’s filesystem to do its job, so we’ve done away with these concepts almost entirely. It adds only a few megabytes to the overall redistributable application’s installed footprint and won’t interfere with any pre-installed web browsers on the user’s machine.

      Nuanti will be offering commercial and community support and is anticipating involvement from the gaming industry and homebrew programmers.

      In the mid term, we aim to submit components of Meta to the WebKit Open Source project, where our developers are already actively involved in maintaining various subsystems.

      Find out more

      Today we’re launching and two mailing lists to get developers talking. We’re looking to make this site a focal point for embedders, choc-full of technical details, code samples and other resources.

      The post WebKit Meta: A new standard for in-game web content appeared first on Alp Toker.

      By alp at June 12, 2008 09:35 AM

      April 21, 2008

      Acid3 final touches

      Alp Toker

      Recently we’ve been working to finish off and land the last couple of fixes to get a perfect pixel-for-pixel match against the reference Acid3 rendering in WebKit/GTK+. I believe we’re the first project to achieve this on Linux — congratulations to everyone on the team!

      Epiphany using WebKit r32284

      We also recently announced our plans to align more closely with the GNOME desktop and mobile platform. To this end we’re making a few technology and organisational changes that I hope to discuss in an upcoming post.

      The post Acid3 final touches appeared first on Alp Toker.

      By alp at April 21, 2008 02:38 AM

      April 06, 2008

      WebKit Summer of Code Projects

      Alp Toker

      With the revised deadline for Google Summer of Code ’08 student applications looming, we’ve been getting a lot of interest in browser-related student projects. I’ve put together a list of some of my favourite ideas.

      If in doubt, now’s the time to submit proposals. Already-listed ideas are the most likely to get mentored but students are free to propose their own ideas as well. Proposals for incremental improvements will tend to be favoured over ideas for completely new applications, but a proof of concept and/or roadmap can help when submitting plans for larger projects.

      Update: There’s no need to keep asking about the status of an application on IRC/private mail etc. It’s a busy time for the upstream developers but they’ll get back in touch as soon as possible.

      The post WebKit Summer of Code Projects appeared first on Alp Toker.

      By alp at April 06, 2008 08:40 PM

      March 27, 2008

      WebKit gets 100% on Acid3

      Alp Toker

      Today we reached a milestone with WebKit/GTK+ as it became the first browser engine on Linux/X11 to get a full score on Acid3, shortly after the Acid3 pass by WebKit for Safari/Mac.

      Epiphany using WebKit r31371

      There is actually still a little work to be done before we can claim a flawless Acid3 pass. Two of the most visible remaining issues in the GTK+ port are :visited (causing the “LINKTEST FAILED” notice in the screenshot) and the lack of CSS text shadow support in the Cairo/text backend which is needed to match the reference rendering.

      It’s amazing to see how far we’ve come in the last few months, and great to see the WebKit GTK+ team now playing an active role in the direction of WebCore as WebKit continues to build momentum amongst developers.

      Update: We now also match the reference rendering.

      The post WebKit gets 100% on Acid3 appeared first on Alp Toker.

      By alp at March 27, 2008 09:06 PM

      March 15, 2008

      Bossa Conf ’08

      Alp Toker

      Am here in the LHR lounge. In a couple of hours, we take off for the INdT Bossa Conference, Pernambuco, Brazil via Lisbon. Bumped in to Pippin who will be presenting Clutter. Also looking forward to Lennart‘s PulseAudio talk amongst others.

      If you happen to be going, drop by on my WebKit Mobile presentation, 14:00 Room 01 this Monday. We have a small surprise waiting for Maemo developers.

      WebKit Mobile

      The post Bossa Conf ’08 appeared first on Alp Toker.

      By alp at March 15, 2008 03:29 AM