Firefox 3 beta 4 now available for testing

Firefox 3 is closer to the finish line with the release of beta 4 tonight.

The release, posted as expected Monday evening, offers testers a variety of enhancements included more refined user interfaces for Windows, Mac and Linux, enhanced search in the Download Manager, performance improvements via the new JavaScript engine, and new features including an adaptive location bar and offline storage for web applications, according to a brief statement posted on the Mozilla developer's web site.

"This is the twelfth developer milestone focused on testing the core functionality provided by many new features and changes to the platform scheduled for Firefox 3," wrote Mike Beltzner, a Mozilla Firefox developer.

Aside from the graphically enhanced welcome window for testers, beta 4 offers more than 900 enhancements from the previous beta including "drastic" improvements to performance and memory usage, according to the release notes.

While beta 3 showed off some of the initial UI perks for specific operating systems, beta 4 offers better integration with Windows Vista, including native use of widgets in the browser and forms. The full incorporation of the formerly known "Proto" add-on gives beta 4 a Mac OSX look-and feel including support for OS X widgets and spell-checker in web forms as well as support for Growl for notifications and updates. It also includes a combined back and forward control for easier navigation between web pages, similar to the one built-into the Vista beta 3 version of Firefox 3, and also now support the native GTK theme for Linux desktops.

The code for Beta 5 is planned to be frozen on March 18. Firefox 3 is expected to be released in early 2008 but the Mozilla leaders have not yet slated a tentative date for the final release.