The Guide shows you How to Install Firefox Nightly Browser i686 for Ubuntu 12.04 Precise Pangolin LTS 32-bit Desktop.
The Firefox Nightly Version can Coexist with the Others Firefox Versions without Troubles, this Mean that Once Fired Up it Will Just Load the Default Firefox Environment.
More than this once installed it will Plug-In the Firefox Nightly Channel and so will follow to be Automatically Updated.
With Firefox Nightly you can get a sneak peek at the next generation Web Browser, and help Mozilla to make the best Browser it can be.
Especially relevant: Nightly is an Unstable Testing and Development Platform.
Inside you find also detailed instructions about How to Create a Launcher for the Firefox Nightly Browser on Ubuntu Desktop.