Ubuntu gets its stability from heavily testing new versions of software. However, if you want to risk some instability and try out the latest versions of your favourite programs, we’ll show you how!

Using these newer packages requires using software sources outside from the normal Ubuntu repositories. Fortunately, there are hundreds, and adding them to Ubuntu is extremely easy!

These other software sources are called Personal Package Archives (PPAs). In most cases, searching for the software you want to upgrade and the word “ppa” will get you to a page that tells you the name of the PPA and some extra details. All that you really need is the name of the PPA.

In our example, we’re going to use the PPA for daily builds of Mozilla Firefox. The PPA name is ppa:ubuntu-mozilla-daily/ppa.

Note: The method described below is only valid for Ubuntu 9.10 and above. For earlier versions of Ubuntu, use our earlier guide for adding extra repositories.

Just for reference, before we add the PPA, with the latest updates our version of Firefox is 3.6.10.

Open a terminal window (either Applications > Accessories > Terminal or Ctrl+Alt+T) and enter the following line

sudo add-apt-repository <name of PPA>

which, in our case, is

sudo add-apt-repository ppa:ubuntu-mozilla-daily/ppa

Now, when we open the Update Manager (System > Administration > Update Manager) and click on Check, we get updates for Firefox.

Installing those updates gives us the latest version of Firefox!

This PPA also happens to include other packages, including the Firefox 4.0 beta. With a quick sudo apt-get install firefox-4.0 we can now try out the latest beta version of Firefox.

PPAs are a great way to selectively choose which software you want to risk updating to the latest version. What PPAs do you use? Let us know in the comments!