First Look: Firefox 3.0 Beta 5

Mozilla's latest Web browser, Firefox 3 Beta 5, announced last Wednesday, brings new features to the table. Beta 5 expands on the current stable version that is notable for advanced security, usability features (such as tabbed browsing and built-in pop-up blocking) and a modular extension system for increased functionality.

Beta 5 has some limited functionality in addition to its new features. It was mostly released to gather feedback from Web developers. New browser features include improved SVG/CSS, improved color handling and offline support for Web applications, with a full list described here.

Unlike its predecessors and Microsoft Internet Explorer 7, Firefox 3 passed the Acid 2 test with ease, while scoring 71/100 on Acid 3 (which no current browser can fully pass). These results reflect enhancements made to Firefox's rendering engine, particularly due to CSS and DOM improvements. JavaScript 1.8 support is also introduced in this beta, along with many other developer features.

Firefox 3 is not quite usable as a day-to-day browser in its Beta 5 form. Many of my extensions were broken during the upgrade process due to incompatibilities between Firefox 2 and 3. Most notably, Adblock and Adblock Plus were incompatible with Beta 5. These sorts of limitations will be resolved as extension developers update their projects.

On the other hand, many of my other extensions, such as Web Developer and IEtab, continued to work due to the availability of new versions. Developers using this beta will likely encounter such limitations on a case-by-case basis. For this reason, I recommend that prospective users make sure that their favorite extensions are compatible, or wait for the full release, to avoid inconvenience.

Firefox 3 revamped the icon theme and appearance of the user interface that was present in Firefox 2. While the new interface looks nice, I found minor fault with the new RSS feed icon.

The default icon theme no longer uses the standard RSS icon that started with Firefox and has since been adopted by Microsoft and Opera. While the RSS feeds work the same as before and the icons can be replaced with different themes, using standard icons for default settings definitely helps in ease of identification. For this reason, I hope that the original icon is restored by the time the final build comes out.

Firefox 3 looks like a great browser that will surpass its predecessors and continue to challenge the competition. However, due to the extension problems and beta status, I would hold off using it on production systems until the final release.

About the Author

Will Kraft is a Web designer, technical consultant and freelance writer. He can be reached at [email protected]. Also, check out his blog at