Overview
- SteamOS architect Pierre-Loup Griffais says Valve initiated the FEX emulator and has funded it from the start.
- Valve began pursuing ARM support around 2016–2017, anticipating nearly a decade of work to make existing libraries playable.
- An ARM version of SteamOS will use an ARM‑aware Proton and include FEX to translate x86 Windows games on ARM hardware.
- Valve aims to reduce porting work and expand device options such as ultraportables and handhelds, and third‑party Android projects already use FEX even as phones are not a current focus.
- Compatibility gaps persist, with anti‑cheat blocking some multiplayer titles, and any ARM-based successor to the Steam Deck remains speculative.