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 12.2. This is the current version.
If you are still looking to install openSUSE 12.1, it is still possible to obtain it from obtaining openSUSE 12.1.
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.