The Firefox 4 stable is coming with a new interface, HTML5 support, 3D on the web, faster startup times and graphics rendering, and other goodness. Although the official site has not yet announced this final release, ftp downloads has come out.

See what’s new in Firefox 4:

Download Firefox4 via ftp:

Firefox4.tar.bz2 for Linux 32-bit
Firefox4.tar.bz2 for Linux 64-bit
For mac and Win32: ftp://ftp.mozilla.org/pub/firefox/releases/4.0/

Firefox 4 extensions: http://linux.softpedia.com/get/Internet/Firefox-Extensions/

The best way for Ubuntu users to install Firefox 4 is update from firefox-stable ppa by:(supports 10.04 and 10.10)

sudo add-apt-repository ppa:mozillateam/firefox-stable
sudo apt-get update
sudo apt-get install firefox