You can directly download the Firefox 4 final build from Mozilla FTP servers now. Once the Firefox 4 officially announce you will be able to update your Firefox directly by visiting Help Menu > Check for Updates.
Versions for Windows, Mac OS X, and Linux are available from Fileforum: the Windows version already has over 61,000 downloads in only a few hours.
Firefox 4 has spent a long time in development stages. The first beta of the browser was released in July of last year, and debuted an overhauled user interface, support for the HD HTML5 video tag using the WebM format, a new add-ins manager, crash protection and performance upgrades, and a host of security fixes.
The biggest change is the placement of the tabs on the top of the browser window, which Mozilla said had less to do with some arbitrary redesign, and more with the “evolution of the web as a platform.”
A dozen official beta releases followed over the next six months, culminating with the release of the first release candidate earlier this month. In terms of performance however, it is said that Microsoft’s Internet Explorer 9 may actually be faster.
Download Firefox 4 for Windows
Download Firefox 4 for Mac OS X
Download Firefox 4 for Linux (x86, x64)