Get You Some SteamOS Beta Now, Debian-Based Platform Available for Download
"SteamOS beta is an early, first-look public release of our Linux-based operating system. The base system draws from Debian 7, code named Debian Wheezy," Valve explains. "Our work builds on top of the solid Debian core and optimizes it for a living room experience. Most of all, it is an open Linux platform that leaves you in full control. You can take charge of your system and install new software or content as you want."
Anyone and everyone is free to download SteamOS, though Valve says to expect some rough edges at this early stage. Furthermore, Valve points out that SteamOS as currently offered "is definitely not a finished product ready for a non-technical user," so you probably shouldn't nuke Windows (or whichever OS you're using) on your daily driver in favor of SteamOS. If you have a secondary rig, however, go have a blast.
One thing you should be aware of is that SteamOS is designed and optimized for the living room. Some of it is proprietary software, including 3rd party proprietary drivers, though you can still access a standard Linux desktop, Valve says. If you're ready, go ahead and grab it right here.