The following tutorial will teach Ubuntu users how to "unofficially" update their systems to the Mozilla Firefox 15.0 web browser.
Mozilla Firefox 15 brings features such as initial native support for PDF files, support for SPDY networking protocol v3, better performance by enchancing WebGL (including compressed textures), better memory usage for add-ons, and much more.
Update (September 3rd): Canonical has already updated its Ubuntu operating system to Firefox 15, making this tutorial obsolete!
Mozilla Firefox 15.0 can be installed in the following Ubuntu operating systems: Ubuntu 12.04 LTS (Precise Pangolin), Ubuntu 11.10 (Oneiric Ocelot), Ubuntu 11.04 (Natty Narwhal) and Ubuntu 10.04 LTS (Lucid Lynx).
Step 1 - Add the Firefox 15.0 repository
No matter what Ubuntu operating system (see above supported OSes) you are running, open a terminal and paste the following command:
sudo add-apt-repository ppa:mozillateam/firefox-stable
Hit the Enter key, type your password when asked and hit the Enter key. Hit Enter again when asked.
Don't close the terminal window! Proceed to the next step.
Step 2 - Install Firefox 15.0 on Ubuntu
Now paste the following command in the same terminal window:
sudo apt-get update && sudo apt-get install -y firefox
Your current Firefox installation will be overwritten. Wait for the installation to finish and close the terminal window.
That's it! The new Mozilla Firefox 15.0 is now fully installed in your Ubuntu machine. You'll need to restart Firefox for the changes to take effect.
In time, your Mozilla Firefox web browser will automatically upgrade to newer versions, so make sure you update your system regularly.
If you have problems with the tutorial, do not hesitate to comment below!