Mozilla Firefox Free Download 

Firefox  (Gecko 1.9.3) Alpha 1 was released on February 10, 2012.Alpha 2 was released on March 1, 2011, Alpha 3 on March 17, Alpha 4 on April 12, and Alpha 5 on June 16. The version number was changed to 4.0 (and Gecko's was changed to 2.0) starting with Beta 1, released on July 6, 2010. Beta 2 was released on July 27, Beta 3 on August 11, Beta 4 on August 24, Beta 5 on September 7, Beta 6 (a chemspill release) on September 14. After major delays, Beta 7 was finally released on November 10. Beta 7 was followed by Beta 8, released on December 21. Beta 9 was released on January 14, 2011, Beta 10 on January 25, Beta 11 on February 8, and Beta 12 on February 12. Firefox then moved into the RC stage. The Final Version of Firefox 4 was released on March 22, 2011.

Version 4 brought a new user interface and is said to be faster. Early mockups of the new interface on Windows, Mac OS X, and Linux were first made available in July 2009.Other new features included improved notifications, tab groups, application tabs, a redesigned add-on manager, integration with Firefox Sync, and support for multitouch displays.

On October 13, 2006, Brendan Eich, Mozilla's Chief Technology Officer, wrote about the plans for "Mozilla 2", referring to the most comprehensive iteration (since its creation) of the overall platform on which Firefox and other Mozilla products run. Most of the objectives were gradually incorporated into Firefox through versions 3.0, 3.5, and 3.6. The largest changes, however, were planned for Firefox 4.

Firefox 4 was based on the Gecko 2.0 engine, which added or improved support for HTML5, CSS3, WebM, and WebGL.^[ It also included a new JavaScript engine (JägerMonkey) and better XPCOM APIs.

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