Firefox 3 Beta 2 is a developer preview release of Mozilla’s next generation Firefox browser and is being made available for testing purposes only.
These beta releases are targeted to Web developers and our testing community to gain feedback before advancing to the next stage in the release process. The final version of Firefox 3 will be released when we qualify the product as fully ready for our users.
Firefox 3 Features
Firefox 3 is based on the new Gecko 1.9 Web rendering platform, which has been under development for the past 28 months and includes nearly 2 million lines of code changes, fixing more than 11,000 issues. Gecko 1.9 includes some major re-architecting for performance, stability, correctness, and code simplification and sustainability. Firefox 3 has been built on top of this new platform resulting in a more secure, easier to use, more personal product with a lot under the hood to offer website and Firefox add-on developers.
More Features check here
Installing Firefox3.0 beta2 in ubuntu
Preparing your system
sudo apt-get install libstdc++5
Now you need to take backup of your old firefox prferences
sudo cp -R ~/.mozilla ~/.mozillabackup
Now you need to download firefox 3.0b2 from here
Now you have firefox-3.0b2.tar.bz2 file
Unzip the .tar.bz2 file in /opt directory using the following command
sudo tar -C /opt -jxvf firefox-3.0b2.tar.bz2
Now you need to link the plugins using the following command
sudo ln -s /usr/lib/mozilla-firefox/plugins/* .
Now you need to create a link to your new firefox launcher using the following command
sudo dpkg-divert --divert /usr/bin/firefox.ubuntu --rename /usr/bin/firefox
sudo ln -s /opt/firefox/firefox /usr/bin/firefox
sudo dpkg-divert --divert /usr/bin/mozilla-firefox.ubuntu --rename /usr/bin/mozilla-firefox
sudo ln -s /opt/firefox/firefox /usr/bin/mozilla-firefox
Installation of firefox 3.0b2 is completed.