Firefox 3 Beta 3 offers numerous features for developers

Firefox 3 Beta 3 expands its already robust support of Web standards while adding its own features. Take Firefox 3 Beta 3 for a test drive today to get a better idea of what to expect.

There was a common thread to the reader feedback about my article on Safari 3: Developers are loyal to Firefox. Firefox's support for customization and standards, along with plenty of add-ons, has made it a favorite among developers; however, this support has been strained as other browsers have caught up.

Firefox 3 Beta 3 is now available, and there are plenty of new features that will interest Web developers.

Web development

When you support multiple browsers, it means knowing what browsers can and cannot do. The next version of Firefox adds support for a variety of Web standards, as well as its own extensions.

Firefox 3 Beta 3 is built on top of Gecko 1.9, which is the new version of Firefox's HTML rendering engine. Furthermore, Gecko 1.9 can pass the Acid 2 test.

The latest version of Firefox includes many changes of interest to developers. The following list provides an overview:

  • Animated PNG (APNG): The animated PNG image format is now supported.
  • Canvas changes: You may draw text in a canvas, as well as use transform-related events.
  • Cross-site requests: Supports the W3C standard for allowing cross-site requests via the XmlHttpRequest object.
  • CSS: A variety of CSS features that were previously not supported are now supported.
  • DOM: Notable DOM features are now supported.
  • EXLST: XSLT extensions are now supported.
  • JavaScript 1.8: The browser supports version 1.8 of the default client scripting language. A notable change is discontinued support for the non-standard Script object. Notable changes to the JavaScript engine are a native JSON parser and Web-based protocol handlers.
  • Microformat support: The browser now includes a data manager for the Microformat standard.
  • Partial HTML 5 support: Certain aspects of the HTML 5 standard are supported, including WHATWG support, which encompasses offline/online support. This provides online and offline events in the <BODY> element, as well as more features. Also, the new activeElement and hasFocus attributes and drag-and-drop events are supported.
  • Enhanced XUL support: A variety of new XUL elements have been added and existing features have been enhanced.
  • The introduction of the Places API: It replaces the history and bookmarks APIs in previous versions, making it possible to develop add-ons that interact with bookmarks and browsing history.

Firefox's add-on architecture is the feature that pushes it to the top of the browser heap. The list of add-ons is overwhelming -- there's something for everybody. A good example is Firebug. On the other hand, the proliferation of add-ons has added to the performance issues.

There are a variety of improvements in Firefox 3, which include the following: Enhancements to Cross Platform Component Object Model (XPCOM) that includes a cycle collector to address memory leaks; additional improvements include a way to secure add-on updates; a new thread manager; and a new approach to localization.


Firefox 3 promises a smaller memory footprint and plenty of performance improvements. When I loaded Firefox 3, I noticed the drastic performance improvement over version 2. I was impressed with the quick application startup, as well as pages loading without delay.

On the memory issue, I use a system with 2 gigs of RAM, so noticing a memory problem would be hard. However, I did monitor memory usage, and Firefox 3 Beta 3 consistently consumed more than 80 MB of memory when browsing via multiple tabs. I would like to hear your feedback concerning memory usage and whether there are noticeable improvements in the current Beta version.

Another improvement is the download manager, which is a main feature for Web developers who are often downloading new software and applications. The download manager now supports searching and includes more information on the download such as a timestamp and where it was saved.

I love the Firefox feature of maintaining multiple tabs when closing, so the tabs appear the next time you open the browser. This is a great feature for developers who rely on the Web for research, testing, and so forth.

Choose your platform

Another great feature of Firefox is its support of multiple platforms. Firefox 3 Beta 3 is available as a free download for Windows, Linux, and Mac OS X. Once the download is complete, the installation is as easy as point-and-click and then choosing your options and the installation directory.

Go for a test drive

Beta programs provide an avenue to examine software before its final release. It is interesting to peruse the list of bug fixes through the alpha and beta phases of Firefox 3.

Mozilla has taken its time with Firefox 3 Beta 3, which is another sign that it's trying to work out all of the bugs. The company plans to release Beta 4 before a final commercial version.

Firefox 3 Beta 3 expands its already robust support of Web standards while adding its own features. Take Firefox 3 Beta 3 for a test drive today to get a better idea of what to expect.

Are you currently using the current Beta or a previous version of Firefox? Do you foresee yourself adopting Firefox 3 when it is released? Post your comments in the Web Developer article discussion.

Tony Patton began his professional career as an application developer earning Java, VB, Lotus, and XML certifications to bolster his knowledge.


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By Tony Patton

Tony Patton has worn many hats over his 15+ years in the IT industry while witnessing many technologies come and go. He currently focuses on .NET and Web Development while trying to grasp the many facets of supporting such technologies in a productio...