The world's best-loved videogames company, Valve, has announced plans to release its own operating system, SteamOS, built for PCs that plug into your living-room television.
It'll be centred around gaming, but also let you stream music, TV and movies.
Valve is calling SteamOS a "co-operating system", combining the company's impressive digital games distribution platform with an interface designed specifically for TVs, built on a "rock-solid" Linux base.
As well as playing games directly on SteamOS, you'll be able to stream games that are installed on your PC or Mac to your television, and there are family sharing features so that younger members of the household can play your copy of Civilization without deleting your save files but can't get their hands on the slightly less family-friendly Saints Row 3.
But what does SteamOS really mean for your living room?
Valve doesn't get things wrong
What Valve does is worth watching because the company has one of the most solid track records in technology history - perhaps even eclipsing Apple in the extent to which its customers love it.
Between Dota 2, Half-Life, Counterstrike, Portal, Team Fortress 2, Left 4 Dead and Steam itself, Valve has barely ever released a product that hasn't been an enormous success. We'll ignore Ricochet for now.
The company's entry into the living room PC market means that it thinks it can do better than the competition.
That's not surprising - that competition is very weak, with perhaps Apple TV and the Chromebox as its biggest rivals if you're excluding the next generation of consoles like the Xbox One, PS4 and Wii U.
Even if you don't, by making its software platform freely available, Valve is hoping to dramatically increase the pace of innovation in the box that sits under your television.
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Steam on Linux: everything you need to know
One of the persistent myths in gaming is that the once-mighty PC scene is dead.
That couldn't be further from the truth. While Microsoft has around active 48 million Xbox Live users, Valve boasts more than 54 million active user accounts on Steam, which represents what one developer called "the lion's share" of the hardcore PC gaming market. The PC Gaming Alliance estimates there are around a billion PC gamers globally.
Steam has a catalogue of nearly 3,000 titles, with more being added weekly. It matches easily up to consoles when it comes to social features, and also supports user-generated content in a selection of games in the Steam Workshop.
It's available in 185 countries and 25 languages, and has automatic patching and cloud saving across platforms. If you're coming from the console world, you'll be impressed by scale of the community and ecosystem that Valve has managed to quietly build in the shadows of Microsoft, Nintendo and Sony's bombast.
SteamOS is going to hit Microsoft where it hurts
A significant number of Windows users only use the platform because of its gaming prowess. Valve supports Apple's OS X and Linux on Steam, but the catalogue of games is significantly smaller than the Windows one and performance is often sluggish in comparison.
Valve boss Gabe Newell, who worked at Microsoft for 13 years before starting a games company, famously called Windows 8 a "catastrophe" and pledged greater support for Linux in the future.
We're now seeing the fruits of that pledge, with Valve having clearly been hard at work behind the scenes persuading developers to ensure their games work on more platforms - the company says: "Watch for announcements in the coming weeks about all the AAA titles coming natively to SteamOS in 2014".
The company has also promised significant performance increases on SteamOS over Windows.
SteamOS seems, for now, to be designed for your television rather than your desktop. But you can bet that if a more desktop-friendly version appears then at least tens of millions of the billion PC gamers planet-wide will seriously consider ditching Windows entirely. With the rest of the PC market in free-fall, that's very bad news indeed for the folks in Redmond.
SteamOS release date is 'soon'
SteamOS is free and it's going to be released "soon", which in 'Valve Time' could mean anything. But this isn't the only big news from Valve this week - the company has timers ticking down to two other announcements.
The first is expected to be the "Steam Box" we already know is in development - a custom-designed bit of hardware that shows other manufacturers how building a living room PC should be done, a little like Google's Nexus programme.
The third announcement? That's a bit of a mystery. Many gamers are praying for the release of an eagerly anticipated sequel to the Half-Life series, but it's more likely to be either the full release of the company's in-beta Family Sharing programme, or something entirely out of left-field.
If the world wasn't kept guessing, it wouldn't be Valve.
- Now read everything you need to know about the elusive Valve Steam Box console