Valve have announced 13 hardware partners for creating and selling Steam Machines, the computers that will power Steam OS. Steam OS is an open source operating system based on the Linux Debian Kernel that will run a version of Steam designed for living room computers. It'll have a custom controller design to make gaming easier without a mouse and keyboard. You won't necessarily have to buy a Steam Machine to see it in action; when Steam OS launches later this year, you'll be able to build your own computer.