Microsoft’s big focus for Windows is AI integration . Meanwhile, Valve has been not-so-quietly pilfering the entire PC gaming ecosystem from Microsoft, turning the Linux-based SteamOS into a real competitor to Windows. In a few years, gaming laptops may run SteamOS instead of Windows. And Microsoft has no one to blame but itself. Valve’s big PC gaming push is bigger than the Steam Deck handheld , with a new Steam Machine living room PC. PC gaming — even PC games designed and written first and foremost for Windows — is now much bigger than Windows. Surprise, Microsoft: While you were focused on Xbox consoles and cloud gaming, Valve stole your crown jewel. Valve started its push with SteamOS back in 2013 For years, PC gaming has been one of the big reasons to use a Windows PC. Let’s be honest: Apple never took gaming seriously on Macs. Google wasn’t much better, either: The Steam for Chromebooks experience is about to be axed . Microsoft poured so much energy into Xbox consoles as a separate platform from Windows. Valve’s first big attempt to decouple PC gaming from Windows was the original version of its Linux-based SteamOS operating system, released back in 2013. A wave of Steam Machine living room consoles from partners followed shortly thereafter. SteamOS launched in the era of Windows 8, when it looked like Windows might become a locked-down, iPad-style operating system with a focus on touch screens, blocking Valve from offering Steam on Windows. (Steam never ran on the Arm-based Windows RT . Only Microsoft’s own desktop apps, like Microsoft Office, ran on that platform.) Asus/Valve Valve ported its own games — Half-Life 2, Portal, and all that good stuff — to Linux, and Valve’s focus was on convincing game developers to port their games to Linux. In 2013, SteamOS didn’t take off. People didn’t want to buy Steam Machine PCs from partners, and most game developers didn’t want to invest resources in porting their games to an operating system few people were using. But SteamOS helped increase the industry pressure on Microsoft, and the company was forced to pivot and keep Windows an “open” operating system that wasn’t locked to its own Store, like Windows RT was. Microsoft discontinued Windows RT. But, while Steam Machines vanished from the shelves and Microsoft seemed to be playing ball with Windows, Valve kept Steam working on Linux. And Valve had a better plan up its sleeves. Valve’s Proton changed the whole industry The game changer was Valve’s Proton compatibility layer , initially released in 2018. It’s software built into Steam that lets you run Windows games on SteamOS and other Linux-based operating systems. Proton is based on Wine , a Windows compatibility layer for Linux and macOS that has been around for decades. Proton was intriguing at the time, but the initial version wasn’t earth-shattering. I’ve been using Wine since the early 2000s, and it’s always been flaky. Lots of companies have dabbled with Wine, but Valve put in serious effort and stuck with it. Chris Hoffman / Foundry Proton kept improving, and Valve released the SteamOS-based handheld Steam Deck in 2022. To run on the Steam Deck, game developers needed their Windows games to perform well in Valve’s Proton environment on Linux. Now, the majority of games in my Steam library run on Linux. It’s automatic, and I don’t have to tweak anything. PC games often run better on Linux than Windows The industry tends to gloss over how crazy this is: Most Windows PC games now run on Linux, and the biggest name in PC gaming is pushing Linux as an alternative to Windows! Microsoft never expected this. And erstwhile Linux users like myself never expected Wine would become this usable. Benchmarks now show that PC games often perform better on SteamOS than Windows 11 . I’ve experienced similar results when I use a handheld Windows PC like the Lenovo Legion Go S alongside my Steam Deck. I reviewed the Lenovo Legion Go 2 , and Windows really held it back. Microsoft is struggling to catch up with Valve, scrambling to release a full-screen Xbox gaming experience optimized for handheld PCs in Windows . PC gaming is now bigger than Windows The secret to success is often just persistence. As of 2022, Valve was directly paying more than 100 open-source developers to work on Proton and other critical parts of the Linux-based SteamOS operating system, as Valve’s Pierre-Loup Griffais told The Verge . While Microsoft was testing a crypto wallet for Edge , getting excited about the metaverse , and pivoting to AI, Valve was putting serious work into SteamOS as a gaming platform. Anti-cheat software is one of the last strengths of Windows. Many multiplayer games demand kernel-level access to block cheating software. Proton can’t allow this, but game developers often want to support the Steam Deck, and Proton already supports anti-cheat software like Easy Anti-Cheat and BattlEye . Chris Hoffman / Foundry Plus, let’s be honest: Lots of gamers don’t want anti-cheat software to have deep access to their PCs, anyway. These programs function a lot like a rootkit, and Steam now requires developers disclose this on their store pages . If SteamOS doesn’t support this, that may be an advantage, even if it can’t run every game. But, aside from that, Valve has made huge inroads. While Microsoft has been focused elsewhere, most of the PC gaming ecosystem has become portable — something that can move between PCs running Windows, SteamOS, and other Linux distributions. The future: SteamOS for more than gaming? SteamOS is a Linux-based operating system. While Valve has focused on the Big Picture experience for handheld PCs and the forthcoming Steam Machine hardware, you can use SteamOS as a desktop operating system today. Valve gets to piggyback on the whole desktop Linux ecosystem, which is surprisingly mature these days. SteamOS has a desktop environment running KDE Plasma, and you can leave the Steam interface and use it as a desktop PC to run Linux software, including web browsers like Firefox and Chrome. You can install it on a gaming PC, if you want. You can even use the Steam Deck as a desktop PC with a dock . Chris Hoffman / Foundry When Valve’s new Steam Machine launches in 2026, I bet lots of people are going to use the desktop environment to get a Linux-based desktop experience on their TVs. The future could involve laptops and desktop PCs running SteamOS — why not? You can already install them on a desktop PC today! Microsoft is less invested in native Windows apps and more invested in cross-platform web apps, anyway. PC gaming was one of Microsoft’s big moats — the reason you picked Windows is because it was compatible with your hardware and could run all those PC games, even if you were interested in Linux. Windows is about to lose that advantage. And PC manufacturers are beginning to install SteamOS on their own devices . SteamOS is ready to compete on Arm PCs, too Valve is even ready for PCs with Arm processors instead of traditional x86 ones from Intel or AMD. Valve’s Steam Frame is the first Arm PC that will run SteamOS, and it happens to be a standalone VR headset. Valve has been funding the Fex emulator , and SteamOS devices running on Arm hardware will have a version of Proton with a built-in Fex emulator to run Windows PC games written for traditional x86 CPUs on Arm-based versions of Linux. As Valve’s Griffais recently said : “In 2016, 2017, there was always an idea we would end up wanting to [run PC games on Arm hardware], and that’s when the Fex compatibility layer was started, because we knew there was close to a decade of work needed before it would be robust enough people could rely on it for their libraries.” Valve is ahead on gaming handhelds, and now Windows vs. SteamOS looks like the next great console war . At this point, Microsoft can’t put the genie back in the bottle. Microsoft could get serious about gaming on Windows, improving the handheld gaming experience, boosting performance , and turning the next Xbox into a PC that can run PC games from Steam. Microsoft will be competing with Valve either way. Windows is no longer the only choice for PC gaming. It’s funny: Windows 8 seemed designed to cement Microsoft’s hold on Windows as an application platform, and now Microsoft has less control of it than ever.