Mozilla releases the third beta of Firefox 3, eight weeks after it made the last major milestone for its open-source browser.

Mozilla Corp. released the third beta of Firefox 3 Wednesday, eight weeks after it made the last major milestone for its open-source browser, and right on a schedule it set a dozen days ago.

Mike Beltzner, Mozilla's interface designer, touted additions and enhancements to Beta 3 in a post to the company's Web site Tuesday, touting several new or enhanced security features, an improved download manager, one-click bookmarking, offline application support, faster page rendering and new progress on plugging the browser's noted "memory leaks."


Not Ready for Prime Time

As he has previously, Beltzner discouraged casual users from trying the new code. "We do not recommend that anyone other than developers and testers download the Firefox 3 Beta 3 milestone release," he said. "It is intended for testing purposes only."

Mozilla has already committed to at least one more beta before Firefox is allowed to move on to release candidate stage. A week and a half ago, however, Beltzner declined to set a release schedule for the next beta, saying then only that: "Our goal is to do a quick turnaround on Firefox 3 Beta 4."


More Than 1,300 Changes in Beta
In its release notes, Mozilla trumpeted the fact that Beta 3 includes more than 1,300 changes made since mid-December's Beta 2, and boasted that its developers had also plugged over 50 new memory leaks in the last eight weeks.

Firefox has long been criticized by users for consuming increasing amounts of memory the longer it remains open, to the point where the browser hinders overall performance on the computer. The company made leak-plugging a top priority, particularly after a member of the Mozilla board of directors said late last year that memory problems would make it tough to compete in the mobile browser market.

Firefox 3 Beta 3 also uses an XPCOM cycle collector that, said Mozilla, "completely eliminates many more [leaks]." The cycle collector, which periodically checks memory usage and tries to free any unused memory, has been in play since last summer, but as Beta 3 development has proceeded, more of its code has been written, or rewritten, to support the collector.

One noted addition to Firefox 3, however, is still buggy. Places, a souped-up bookmarking and browser history management tool that was once slated for Firefox 2, does not yet allow users to shuffle bookmarks by dragging and dropping. According to notes from a Tuesday Firefox 3 status meeting, Places is stuck.

"Cannot drag-and-drop items across different views/menus," the notes read. "This is blocking on resolution of platform bug 389931, which is a P1 [Priority 1 -- Ed.] blocker regression from the thread manager rewrite, and seemingly unowned (no response from owner since July 2007). This is the cause of much weeping and gnashing of teeth."

Firefox 3 Beta 3 can be downloaded for Windows, Mac OS X and Linux in 32 languages from Mozilla's site.