Mozilla has just released the fourth beta version of its next-generation browser. You can’t help but comparing this new Firefox to Microsoft’s recently released beta version of Internet Explorer 8 and if you closely, the differences are dramatic from a user perspective. While security was the selling point in both Firefox 2 and Internet Explorer 7, added convenience and performance are clearly the headlines for these new browsers. And both browsers reveal a very different design philosophy and understanding what additional convenience features will be appreciated by users.

The fourth beta of Firefox 3 was released yesterday and, at least according to the developers, another round of massive changes has been applied. Firefox’s 3 new Gecko 1.9 engine is already claimed to include more than 12,000 changes over Gecko 1.8x, the engine used in the current stable Firefox 2. Beta 4 is said to integrate more than 900 improvements over Beta 3, which included 1300 changes over Beta 2. The beta process is running at full steam, with another beta version likely to become available later this month, as Mozilla has scheduled the Beta 5 code freeze for March 18.