Following the release of 300 Steam Machine prototypes to select beta testers, Valve has also released the Beta version of their free, Linux-based operating system called SteamOS.
Along with the seeding the software, the company has also put up a list of hardware components that the build (codenamed Alchemist) currently supports. Moreover, they’ve also provided a detailed instruction on how to get ball rolling with SteamOS (found on the same link above).
However, installing the OS on your DIY Steam Machine is one thing, getting it to work properly is a totally different thing altogether. That said, if you don’t know your way around the Linux ecosystem, then it’s best to leave SteamOS to the true geeks for now.
You can download the SteamOS Beta installer by heading over to this link.