In this article I will show you how to install the latest (stable) Firefox, Firefox 20, on your Ubuntu 13.04 Raring Ringtail, Ubuntu 12.10 Quantal Quetzal, Ubuntu 12.04 Precise Pangolin, Linux Mint 14 Nadia and Linux Mint 13 Maya.
Add the Firefox repo:
sudo add-apt-repository ppa:ubuntu-mozilla-security/ppa
Update the system:
sudo apt-get update
Install Firefox:
sudo apt-get install firefox
The latest Mozilla Firefox version is Firefox 21, but it is unstable. If you want to test it, do this:
sudo add-apt-repository ppa:mozillateam/firefox-next sudo apt-get update sudo apt-get install firefox