Earlier this week, Steam announced SteamOS; a complete operating system for games, video and music on a box that can be connected to the living room TV. Steam will partner with hardware makers for Steam Machines, but you can also build your own. It is coming in 2014.
Steam will let everyone build Steam Machines
It begins in 2014. Steam will partner with a range of hardware makers that will build and sell Steam Machines in a range of configurations. You can even build your own PC and install SteamOS.

Steam will let everyone build Steam Machines, including you
Valve says that the SteamOS game consoles will launch beginning in 2014, but they have not been more specific than that. 300 beta testers will be issued a prototype of a Steam game console later this year, and you can apply for the program on Steam’s website.
Valve says that of the nearly 3000 games running on Steam, “hundreds” are already running natively on SteamOS (which is based on Linux). They expect far more games before launch, and they said earlier this week that AAA game studios are committed to the project.
We had expected a few more details to be released by Steam, but they will share more on Friday, most likely its plans for game controllers based on Steam’s closing line; “we have some more to say very soon on the topic of input”.
Learn more about Steam’s plans here.