How to Install Firefox Beta on Ubuntu Linux

                             The Beta release of Mozilla Firefox is supported and can be installed on the following Ubuntu operating systems: Ubuntu 12.10 (Quantal Quetzal), Ubuntu 12.04.1 LTS (Precise Pangolin), Ubuntu 11.10 (Oneiric Ocelot), Ubuntu 11.04 (Natty Narwhal) and Ubuntu 10.04 LTS (Lucid Lynx).

Source:Softpedia