OpenSUSE 12.1
This was the Linux distribution my server was based on. More information is available here.
If you are looking to install openSUSE, you should look at installing openSUSE 12.3. This is the current version.
openSUSE 12.1 support ended on 11th June 2013.
Information
openSUSE 12.1 was released on 16th November 2011. It is an open-source distribution and is free of charge. It is developed by the community and sponsored by Novell.