The Linux-based living room gaming announcements Valve co-founder Gabe Newell promised last week began today with the unveiling of SteamOS, a new Linux-based operating system focused on living room gaming.

"As we’ve been working on bringing Steam to the living room, we’ve come to the conclusion that the environment best suited to delivering value to customers is an operating system built around Steam itself," Valve wrote on a page announcing the upcoming OS. "SteamOS combines the rock-solid architecture of Linux with a gaming experience built for the big screen. It will be available soon as a free stand-alone operating system for living room machines."

Why a new OS? Valve says that with SteamOS, the company has "achieved significant performance increases in graphics processing, and we’re now targeting audio performance and reductions in input latency at the operating system level." The Linux-based platform will also be freely licensable to hardware manufacturers, allowing a wide number of "Steam Box" living room PCs to germinate. Newell has previously called Windows 8 a "catastrophe" for the gaming market, so it's not at all surprising that his company decided to move forward with a more open option under its direct control.

With the vast majority of Steam's thousands of games currently designed to run only on Windows and/or Mac, compatibility is obviously a major concern with any Linux-based system. Valve says that "hundreds" of games are currently running on their new OS (presumably building off current Steam for Linux compatibility) and promises that the coming weeks will see many AAA game announcements with native SteamOS support in 2014 (when living room systems with SteamOS are expected to launch). The OS will also support the full Steam catalog through "in-home streaming," which presumably means remote play from an office PC to a living room TV over a home router.

SteamOS will be fully compatible with existing Steam functions like automatic game updates across machines, Steam Workshop add-ons and marketplaces, in-game chat and friends lists, family sharing across multiple accounts, and more, according to Valve. In addition, Valve says it's "working with many of the media services you know and love" to bring unspecified online music, TV, and movie services to the new OS.

This is one of the first concrete announcements regarding Valve's highly anticipated living room gaming plans since the introduction of "Big Picture" mode last September. Since then, there have been a number of hints and leaks surrounding the existence of "Steam Box" living-room-based gaming PCs, but very little in the way of official announcements.

Valve is currently teasing two more living room-centric announcements on a countdown page. The next bit of news is set to come Wednesday at 1pm Eastern Time.