Valve is in the process of unveiling their plans for living room dominance. Starting today, the company has three phases of information to divulge as far as Steam goes. First up? An operating system.

It looks like the folks at Valve are taking operating system matters into their own hands for their invasion of the living room. Here’s how they describe SteamOS:

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. 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.

SteamOS will be free and available to download soon. It will work “on any living room machine,” and it “will provide access to the best games and user-generated content available.”

SteamOS will be built around four features that are coming soon to both it and the traditional Steam client. They are, according to the new site, as follows…

In-home Streaming

You can play all your Windows and Mac games on your SteamOS machine, too. Just turn on your existing computer and run Steam as you always have – then your SteamOS machine can stream those games over your home network straight to your TV!

Music, TV, Movies

We’re working with many of the media services you know and love. Soon we will begin bringing them online, allowing you to access your favorite music and video with Steam and SteamOS.

Family Sharing

In the past, sharing Steam games with your family members was hard. Now you can share the games you love with the people you love. Family Sharing allows you to take turns playing one another’s games while earning your own Steam achievements and saving your individual game progress to the Steam cloud.

Family Options

The living-room is family territory. That’s great, but you don’t want to see your parents’ games in your library. Soon, families will have more control over what titles get seen by whom, and more features to allow everyone in the house to get the most out of their Steam libraries.

That’s right. You’ll be able to stream your PC games to whatever’s running SteamOS in your living room, you’ll have account profiles, you’ll have family sharing and you’ll be able to turn the SteamOS device into a media center. This is the backbone of a big play, folks.

Phase two of this announcement will happen on Wednesday at 1pm EST. We’ll be all over it. Any guesses on what’s next?