As it announced earlier this week, Valve shipped its 300 Steam Machine prototypes to its randomly selected beta testers late today. That announcement was accompanied by the first public release of SteamOS, the currently-in-beta Linux-based operating system that will power Valve's new gaming-PCs-turned-consoles.
Valve's announcement post has given us a better idea of exactly what SteamOS includes: it's based on Debian 7 ("Wheezy"), which Valve has "optimize[d]... for a living room experience." It comes with the Gnome desktop environment pre-installed, and users are free to download and install other software to the OS as they see fit—while SteamOS is clearly being built with gaming in mind, there's nothing to stop you from loading it up with productivity software and browsers and using it as a work PC, either.
If you'd like to build your own Steam Machine using the Steam OS beta, Valve has put up some basic system requirements and instructions here. The installation process should be no problem for anyone who has a passing familiarity with Linux, though the instructions as they stand require you to destroy all existing partitions and operating systems already on the disk you use. The system requirements are more specific, owing to the early nature of the software, and they hew very closely to the configurations Valve specified for the 300 official beta machines: you'll need a UEFI-enabled 64-bit Intel or AMD-powered PC, 4GB or more of RAM, a 500GB or larger HDD, and an Nvidia GPU. Valve says that AMD and Intel GPU support will be "coming soon," but for now installing SteamOS on your NUC will have to wait. OEMs who would like to build and distribute their own Steam Machines are being encouraged to get in touch with Valve to talk about licensing the proprietary Steam client.
Earlier this week, Ars Senior Reviews Editor Lee Hutchinson and I specced out, ordered, and built our own prototype Steam Machine using Valve's prototype spec list as a guideline. Lee is installing SteamOS on the hardware even as you read this, and his initial impressions about installing and using SteamOS will be posted in the coming days. We'll continue to track SteamOS' development and the various Steam Machine-related announcements as events progress.