Valve’s beta SteamOS will be released for download on Friday 13th December 2013, the same day that 300 lucky US based beta participants receive shipment of their very own Steam Machine (Steam Box).
SteamOS is a freely available open source Linux based Operating System designed from the ground up exclusively for gaming on the big screen TV (“living room experience”). As native Linux gaming is limited and still in it’s infancy, many popular windows games will be made available from SteamOS via in-home streaming. Think of it as the gaming equivalent to Netflix.
Read more about SteamOS and Steam Machines here.
You can download SteamOS here.
Official Steam installation instructions can be found here.
As this is a beta release you should expect some bugs, and will need some basic Linux command line knowledge to troubleshoot. The final polished version is rumored for early 2014.