Over the past week or two, we have been keeping track of the various releases of Firefox 4 including RC1 and RC2, counting down to the official release tomorrow, the 22nd of March. Though it is officially being released tomorrow, it has been made available for download today at the Mozilla FTP servers.
Firefox comes with many new features such App Tabs, hardware acceleration, Firefox Sync and much more.
For Firefox 4 Final Setup in your language, refer to official repository.
Due to heavy demand and traffic, the link may be slow or may even go down for sometime.
Download Firefox 4.0:
Firefox 4.0 for Linux (x86, x64): Mozilla
Firefox 4.0 for Mac: Mozilla