Mozilla announced on Tuesday that the final release version of its Firefox 4 Web browser was available for download. Within its first 24 hours of availability, the browser was downloaded over 6 million times. Microsoft's latest browser release, Internet Explorer 9, was downloaded 2.35 million times in its first 24 hours of availability. Version 4 of the popular Firefox Web browser features a variety of enhancements including a redesigned UI, improved tab management and faster performance. Mozilla's Firefox browser is the second most popular browser in the world according to market share tracker Net Applications. Firefox held a 21.74% global browser share in February, behind Internet Explorer's 56.77% and ahead of No. 3 browser Chrome, which has grown to 10.93% in a very short period of time. Both Internet Explorer and Firefox have seen their shares decrease over the past year, while Google's Chrome browser and Apple's Safari browser have gained popularity. Hit the break for a video highlighting Firefox 4's new features.