The official repositories for a particular version of Ubuntu are composed to contain the latest versions of software packages as of the date of release of that version of Ubuntu. After the release is made, newer versions of software packages do not get added to the repositories, with the exception of security fixes. So, for example, the latest version of Firefox during Ubuntu 8.04 (Hardy) release was 3.0, so the repositories will contain 3.0, even though Firefox 3.5 was released afterwards. Furthermore, even the security patches are usually several days to a week or more behind the official Mozilla releases, due to the time it takes to test and package the software.
It is frequently desirable to get more timely security updates for Mozilla software, or run the latest version, which may not be available in the repositories, due to the new features and improvements. This is where the Ubuntuzilla repository comes in.
More information on the Ubuntuzilla Project page for specific instructions for using this repository to install Firefox, SeaMonkey, and Thunderbird.
Visit project ubuntuzilla
Visit project ubuntuzilla, et get access to the repository hosting the Mozilla builds of the latest official releases of Firefox, Thunderbird, and Seamonkey (available on the Sourceforge project page too).
Other useful links:
- Ubuntuzilla Support Forum (courtesy of the Ubuntu forums)
- Official Ubuntu resources:

