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This article was written by John Daggett. John is a Mozilla contributor and has been working hard with font creators and web developers to improve the state of fonts on the web. This article is a high-level overview of whats different and shows some examples of WOFF in use. A full list of other supporting organizations can be found at the official Mozilla Blog.

In Firefox 3.5 we included support for linking to TrueType and OpenType fonts. In Firefox 3.6 we’re including support for a new font format – the Web Open Font Format, or WOFF. This format has two main advantages over raw TrueType or OpenType fonts.

1. It is compressed, which means that you will typically see much smaller download sizes compared with raw TrueType or OpenType fonts.
2. It contains information that allows you to see where the font came from – without DRM or labeling for a specific domain – which means it has support from a large number of font creators and font foundries.

The WOFF format originated from a collabaration between the font designers Erik van Blokland and Tal Leming with help from Mozilla’s Jonathan Kew. Each had proposed their own format and WOFF represents a melding of these different proposals. The format itself is intended to be a simple repackaging of OpenType or TrueType font data, it doesn’t introduce any new behavior, alter the @font-face linking mechanism or affect the way fonts are rendered. Many font vendors have expressed support for this new format so the hope is this will open up a wider range of font options for web designers.

Details on Differences between TrueType, OpenType and WOFF

First, compression is part of the WOFF format so web authors can optimize the size of fonts used on their pages. The compression format is lossless, the uncompressed font data will match that of the original OpenType or TrueType font, so the way the font renders will be the same as the original. Similar compression can be achieved using general HTTP compression but because compression is part of the WOFF format, it’s simpler for authors to use, especially in situations where access to server configuration is not possible.

Second, the format includes optional metadata so that a font vendor can tag their fonts with information related to font usage. This metadata doesn’t affect how fonts are loaded but tools can use this information to identify the source of a given font, so that those interested in the design of a given page can track down the fonts used on that page. Fonts in WOFF format are compressed but are not encrypted, the format should not be viewed as a “secure” format by those looking for a mechanism to strictly regulate and control font use.

Note: until Firefox 3.6 ships, users can test the use of WOFF fonts with Firefox nightly builds.

Examples

Below is a simple example that shows how to construct an @font-face rule that links to a WOFF font. To support browsers that only support direct linking to OpenType and TrueType fonts, the ’src’ descriptor lists the WOFF font first along with a format hint (”woff”), followed by the TrueType version:

/* Gentium (SIL International) */
 
@font-face {
  font-family: GentiumTest;
  src: url(fonts/GenR102.woff) format("woff"),
       url(fonts/GenR102.ttf) format("truetype");
}
 
body {
  font-family: GentiumTest, Times, Times New Roman, serif;
}

Structured this way, browsers that support the WOFF format will download the WOFF file. Other browsers that support @font-face but don’t yet support the WOFF format will use the TrueType version. (Note: IE support is a bit trickier, as discussed below).　As WOFF is adopted more widely the need to include links to multiple font formats will diminish.

Other examples below demostrate the use of WOFF formatted fonts but each example has been constructed so that it will work in any browser that supports @font-face, including Internet Explorer.

A font family with multiple faces

Using a Postscript CFF font

African Language Display

Below is an example of how downloadable fonts can be used to render languages for which font support is usually lacking. The example shows the UN Declaration of Human Rights, translated into two African languages, and how these render with default browser fonts vs. with a downloadable font suited for rendering these languages.

Note that in one of these examples that the font size goes from a 3.1MB TTF to a 1MB WOFF font and in the other from a 172KB TTF to an 80KB WOFF file.

Another Postscript CFF font

An example in Japanese

Working With Other Browsers

Firefox 3.6 will be the first shipping browser to support the WOFF format so it’s important to construct @font-face rules that work with browsers lacking WOFF support. One thing that helps greatly with this is the use of format hints to indicate the format of font data before it’s downloaded; browsers that don’t recognize a given format simply skip data in a format they don’t support.

Internet Explorer, including IE8, only supports the EOT font format and only implements a subset of the @font-face rule descriptors. This makes creating cross-platform @font-face rules that work with IE especially tricky. One solution is to make different rules for IE:

@font-face {
  font-family: GentiumTest;
  src: url(fonts/GenR102.eot);  /* for IE */
}
 
@font-face {
  font-family: GentiumTest;
  /* Works only in WOFF-enabled browsers */
  src: url(fonts/GenR102.woff) format("woff"); 
}

One minor downside of this is that IE doesn’t understand format hints and doesn’t parse @font-face URL’s correctly, it treats format hints as part of the URL, so web authors using the @font-face rules above will see the following in their access logs:

GET /fonts/GenR102.eot HTTP/1.1" 200 303536
GET /fonts/GenR102.woff)%20format(%22woff%22) HTTP/1.1" 404 335

IE successfully pulls down and uses the EOT version of the font but also tries to pull down the WOFF font with the format hint included in the URL. This fails and doesn’t affecting page rendering but it wastes valuable server resources. For more discussion, see Paul Irish’s blog post for one interesting workaround.

Another problem is that IE currently tries to download all fonts on the page, whether they are used or not. That makes site-wide stylesheets containing all fonts used on site pages difficult, since IE will always try to download all fonts defined in @font-face rules, wasting lots of server bandwidth.

Further Resources

Documentation

Latest draft WOFF specification
Original blog post on using @font-face
CSS3 Fonts working draft
MDC @font-face documentation

Tools

Jonathan Kew’s sample encoding/decoding code
woffTools – tools for examining and validating WOFF files
FontTools/TTX – Python library and tool for manipulating font data
Web-based font subsetting tool

General @font-face Examples

CSS @ Ten: The Next Big Thing
Example layout using Graublau Sans
Examples of Interesting Web Typography
The Elements of Typographic Style Applied to the Web

Font Resources

Font Squirrel
10 Great Free Fonts for @font-face
40 Excellent Free Fonts by Smashing Magazine

Thomas Saunders of modern-carpentry has a very nice HTML5 demo, making waves with html5, showcasing the power of Canvas as well as Processing.js.

modern carpentry rides the html5 canvas wave

Thomas says:

I was challenged at work to create something that “floats naturally”. After a while of confusion in my pursuit of “natural floating” or whatever, I came up with the idea that I needed a tool to investigate my confusion. This project is a result of my trying to build that tool.

It was initially built as a Flash/Flex application, which you can see here. Later on, however, I became interested in HTML5 and the Canvas tag and decided to port the application to JavaScript and HTML (with the help of jQuery, and also Processing.js, of course…). The transition went fairly well, and I ended up with a JS/HTML version of the application that I actually think is cooler than the original Flash version.

In the end, I came up with both something that “floats naturally” and also a serendipitous encounter with the simplicity of working with only HTML and JavaScript, which has been very rewarding.

The ever-energetic Felipe Gomes was nice enough to intern with Mozilla this summer in between busy semesters in Brazil. During that time he’s been working on multi-touch support for Firefox on Windows 7. A nice result of that work is that he’s also found ways to bring multi-touch support to the web. He’s made a short video and written up some short technical information to go with it.

This post has also been cross-posted to Felipe’s personal blog.

Multitouch on Firefox from Felipe on Vimeo.

I’ve been anxious to demonstrate the progress on our multi-touch support for Firefox, and this video showcases some possible interactions and use cases for what web pages and webapps can do with a multi-touch device.

We’re working on exposing the multi-touch data from the system to regular web pages through DOM Events, and all of these demos are built on top of that. They are simple HTML pages that receive events for each touch point and use them to build a custom multi-touch experience.

We’re also adding CSS support to detect when you’re running on an touchscreen device. Using the pseudo-selector :-moz-system-metric(touch-enabled) you can apply specific styles for your page if it’s being viewed on a touchscreen device. That, along with physical CSS units (cm or in), makes it possible to adjust your webapp for a touchscreen experience.

Firefox 3.6 will include the CSS property, but is unlikely to include the DOM events described below.

Here is an example of what the API looks like for now. We have three new DOM events (MozTouchDown, MozTouchMove and MozTouchRelease), which are similar to mouse events, except that they have a new attribute called streamId that can uniquely identify the same finger being tracked in a series of MozTouch events. The following snippet is the code for the first demo where we move independent <div>s under the X/Y position of each touch point.

var assignedFingers = {};
var lastused = 0;
 
function touchMove(event) {
    var divId;
    if (lastused < = 4)
        return;
 
    if (assignedFingers[event.streamId]) {
        divId = assignedFingers[event.streamId];
    }
    else {
        divId = "trackingdiv" + (++lastused);
        assignedFingers[event.streamId] = divId;
    }
 
    document.getElementById(divId).style.left = event.clientX + 'px';
    document.getElementById(divId).style.top  = event.clientY + 'px';
}
 
document.addEventListener("MozTouchMove", touchMove, false);
document.addEventListener("MozTouchRelease",
                          function () { lastused--; }, false);

On the wiki page you can see code snippets for the other demos. Leave any comments regarding the demos or the API on my weblog post. We really welcome feedback and hope to start some good discussion on this area. Hopefully as touch devices (mobile and notebooks) are getting more and more popular we’ll see new and creative ways to use touch and multitouch on the web.

As covered on the Mozilla Developer Center, Firefox 3.6 Alpha 1 is now available for download. And we’ve been busy since Firefox 3.5.

Web developers will be interested in a number of features that are new in Firefox 3.6 Alpha 1:

• The TraceMonkey JavaScript engine has continued to get faster.
• We’ve made a huge number of improvements to overall DOM and element layout performance. In some cases we’re much, much faster. We’ll cover details on those in a later post.
• The compositor landing has made it possible to fix a large number of interactions between web content, CSS and plugins. We’ll be talking about this in a later post as well.
• We now support the -moz-background-size CSS property which lets you set the size of background images.
• We now support CSS Gradients.
• We now support multiple background images.
• We now support the rem unit as a CSS unit.
• image-rendering is supported for images, background images, videos and canvases.
• We now send a reorder event to embedded frames and iframes when their document is loaded.
• We’ve removed the getBoxObjectFor() method. It was non-standard and exposed all kinds of non-standard stuff to the web.
• We now send a hashchange event to a page whenever the URI part after the # changes.
• We now have Geolocation address support for user-readable position information.
• We now support the complete attribute on document.readystate.

You can keep track of this list and other features for XUL and add-ons developers on the Firefox 3.6 for developers page on developer.mozilla.org

Unlike the year that passed between Firefox 3 and Firefox 3.5, we expect that this 3.6 release will be released in a small number of months. Our main focus for the 3.6 release will be end-user perceived performance, TraceMonkey and DOM performance and new web developer features.

Enjoy and test away!

Recently Arun Ranganathan, one of the members of the Mozilla Evangelism team, created a video for MozCamp Mumbai. It’s about 20 minutes long and he covers a huge number of topics: the new @font-face CSS property and how it affects the ability for people to receive properly localized content, the differences between the various standards efforts (there’s more than just HTML5) and gives some demos that show what’s possible when you combine video with the web.