What distributions are supported by Steam?
Currently, Steam for Linux is only supported on Ubuntu 12.04 LTS or 12.10 with the Unity, Gnome, or KDE desktop. Additional distributions will be examined for support as time permits. For more information on Steam for Linux, see https://wiki.ubuntu.com/Valve.
If you are running another distrubiton of Linux we will be unable to offer support as these are not officially supported. If you are having trouble running Steam for Linux on another distribution we recommend switching to Ubuntu 12.04 LTS or 12.10 with the Unity, Gnome, or KDE desktop.