"After twelve betas and two RCs (Release Candidates), Mozilla has finally announced and released the final RTM/RTW version of next generation Firefox 4 web browser. Firefox has redesigned user interface (GUI) especially to functionality of tabs management, greatly improve performance and page rendering speed with Gecko 2.0 engine and new JägerMonkey JavaScript engine, in addition to GPU hardware acceleration support. Another feature, Firefox Sync allows user to synchronize settings, passwords, bookmarks, history, open tabs and other customizations across multiple devices."

Firefox 4 for Windows: Firefox Setup 4.0.exe
Firefox 4 for Mac OS X: Firefox 4.0.dmg
Firefox 4 for Linux (x86-x64): firefox-4.0.tar.bz2