Mozilla is now out with its latest Firefox 3 milestone release - Beta 3. With most of the Firefox 3 Betas and Alphas to date there have been changes that you would notice if you looked for them and actually started to use the browser.

With Firefox 3 Beta 3 (FFb3) you get hit with a big change right away. The UI itself is 'refreshed' with new forward,back and refresh buttons. Though the UI change is among the most obvious in FFb3, Mozilla actually claims that the release includes some 1300 changes over the Beta 2 release which came out nearly two months ago.

Among the changes in FFb3 are more than 50 new memory usage improvements in the browser. The continuing memory improvements in each Beta release of Firefox 3 are coming in part from the XPCOM (Cross Platform Component Object Mode) cycle collector that identifies objects that aren't being used and releases them from memory. XPCOM was first deployed as part of the Firefox 3 Beta 1 release in November.

Beyond just improving performance by fixing memory leaks, Mozilla also claims that Beta 3 has an additional 90 changes over Beta 2 that increase the browser's page rendering speed. Firefox 3 uses the Cairo 2-D graphics library which is a departure from Firefox 2.0's gfx graphics infrastructure.

Mozilla has also continued to make improvements in its' Places engine which provides History and Bookmarking capabilities. In Beta 3 they've added additional search functionality when searching History and Bookmarks to include frequency of visits to help improve the search results.

The Beta 3 release is the eleventh milestone release from Mozilla in the Firefox 3 browser development process which has been publicly ongoing since at least October of 2006. A Beta 4 release of Firefox 3 has already been announced and is expected to follow sometime in the next few weeks. Mozilla developer Asa Dotzler has blogged that Firefox 3 will be out 'when it's ready' instead of focusing on a hard deadline or date for delivery.

In stark contrast with the big race between Microsoft and Mozilla ahead of the Firefox 2 and Internet Explorer 7 releases, Microsoft has not yet released a single public milestone of IE 8. Microsoft has however stated as long ago as October of 2006 that IE 8 is in fact in development