SteamOS compatibility expands to Arm hardware and Android APKs

Two new compatibility paths through FEX and Lepton

Ars Technica reports that Valve is deploying two additional compatibility layers for the SteamOS-powered Steam Frame. FEX, Valve's port of the open-source fex-emu project, emulates x86 processor instructions on Arm chipsets. Lepton extends Waydroid to run standard Android APKs through a software container. The report says Valve is also exploring SteamOS versions for other Arm devices. It cites VR.org metadata research finding that 52 of the first 120 games marked “Great on Frame” ran as Android executables translated through Lepton.

SteamOS was chiefly associated with Proton, the compatibility layer used to run Windows games on its Linux-based system; Valve had previously asked developers for bespoke Linux ports for early SteamOS.

The reported addition of FEX and Lepton expands SteamOS compatibility beyond Windows games: FEX translates x86 instructions for Arm hardware, while Lepton runs Android APKs in a software container.

The reported shift would make SteamOS less dependent on ports built specifically for Windows or Linux. It connects the Steam ecosystem to both Arm-based hardware and Android-originated software, particularly standalone VR titles originally made for Android-based Quest headsets.