SteamOS engineer Pierre-Loup Griffais has been a reliable source of information regarding the inner workings of Valve, at least when it comes to the development of the Steam Deck, SteamOS, and now, its new hardware ventures. The latest development is the insider knowledge that Valve has been funding FEX for many years. FEX is an open-source emulator designed to run Windows games on ARM Linux devices (such as Valve’s upcoming Steam Frame VR headset).

Valve has been expanding its horizons lately. The Steam creator has enjoyed a massive amount of success with its Proton compatibility layer to bring Windows games to Linux – it’s also doing the same with Android for Linux, through yet another compatibility layer revealed to be named Lepton yesterday.

Valve’s involvement with FEX

News publication The Verge recently interviewed the Valve developer, and he revealed that Valve has been funding FEX since its inception. For reference, FEX recently celebrated its seventh anniversary. In an official anniversary post, from November 28, Valve is even thanked “for being here from the start,” so this is a pretty open secret at this point.

“That’s right, all the core [FEX] developers have been funded by us since the beginning. We definitely started that project with the idea that it would be something that’s useful for the ecosystem at large, but also something that would be really useful for SteamOS and other applications in the future.”

Pierre-Loup Griffais, Software Engineer at Valve, when asked if Valve funds FEX

Examples of ARM architecture processors include Apple’s silicon (A-series and M-series) and Qualcomm’s Snapdragon series. Both are popular solutions for smartphones and laptops/MacBooks, though these typically aren’t devices we’d recommend for gaming. Right now, x86 architecture-based devices powered by AMD or Intel dominate the gaming space. With the steady development of an emulator like FEX, gaming on ARM becomes a more viable option.

Griffais says Valve “knew there was close to a decade of work needed before it would be robust enough people could rely on it” before adding that the company is “pretty excited to be able to expand PC gaming to include all those options instead of being arbitrarily restricted to a subset of the market”.

“It all started with the same assumption that you’re going to get the same experience on Arm, you’re going to have the same set of games, and you’re going to be able to run them without having to worry about what architecture your computer is using. That was really our goal, to try to reduce barriers for users not having to worry about what games run and for developers to get a starting point for those new devices.”

Pierre-Loup Griffais, Software Engineer at Valve

We figured that the Steam Machine is a great excuse to stop gaming on Windows, but it looks like 2026 is going to be an even bigger year for Linux gaming than we thought, now that we know Valve has an arsenal of tools to push it further. Proton has been doing it for years on the Steam Deck, but the development of Lepton and FEX really builds out the whole package. The Verge even asked about the possibility of SteamOS on phones, and Griffais says he isn’t “discounting any possibility” – but it’s best to start with “living room, handheld, and desktop” devices first.

About the Author

Jack Goodall

At PC Guide, Jack is mostly responsible for reporting on hardware deals. He also specializes in monitors, TVs, and headsets and can be found putting his findings together in a review or best-of guide.