Vanilla is a product of Lussumo:
Documentation and Support.
There's the Valve Steam box, which is a tiny but powerful computer.Gabe and another Valve engineer have said that the Piston isn't actually the SteamBox. They're working with Xi3 on it, obviously, and it's being designed for playing high-end PC games, but the SteamBox itself will be designed and sold directly by Valve, , be running Linux, and eventually work as a server that will let you play different games on different screens. Engadget gallery of Valve's own SteamBox prototypes.