Following up on Monday's announcement of a general purpose, Linux-based, living-room-centric SteamOS, Valve announced that it is "working with multiple partners to bring a variety of Steam gaming machines to market during 2014, all of them running SteamOS." In addition, Valve said that it will be providing 300 prototype boxes to beta testers free of charge before the end of the year.

While Valve has hinted about its plans for living room gaming hardware many times in the past, this is the first official announcement that the company will be working on hardware in the coming year. It's unclear just how involved Valve will be in the design and marketing of the newly announced Steam machines, though. Valve's role could range anywhere from direct input and manufacturing to merely providing the OS and general guidelines for its use.

Valve is remaining mum for now on specs and form factor for both the Steam machines and the beta prototypes, promising only that "we'll tell you more about it soon" and emphasizing that "there will ultimately be several boxes to choose from, with an array of specifications, price, and performance." Those boxes will come from a variety of manufacturers "beginning in 2014," Valve wrote, even though the prototype boxes will be sent out for beta testing this year.

The prototype hardware is being designed for real-world testing during the design process, Valve said, and it won't necessarily be indicative of the final designs for the final Steam machines. "The specific machine we're testing is designed for users who want the most control possible over their hardware," Valve wrote. "Other boxes will optimize for size, price, quietness, or other factors."

To be chosen among the lucky 300 beta testers, Steam users must register with the Steam Universe community and the Steam hardware beta, connect with at least 10 friends on Steam, and use a gamepad for a game in Big Picture mode before October 25. A few beta testers will also be chosen "based on their past community contributions and beta participation." Testers will be able to talk freely and publicly about their prototype units during the test ("that really is the whole point," Valve said).

In addition, others will be able to build their own boxes to test SteamOS when it is available, even getting into the source code of the Linux-based operating system "if you're into that," Valve said. Users will explicitly be able to "hack this box, run another OS, change the hardware, install my own software, [and] use it to build a robot" Valve said in an FAQ. That should ease some concerns about the "openness" of the SteamOS environment announced earlier.

Valve also explicitly clarified that mouse-and-keyboard controls will work with SteamOS and hinted that "we have some more to say very soon on the topic of input." This is very likely a hint at some sort of controller reveal, perhaps during the announcement the company is currently counting down to on Friday.