Modders Bring Steam Frame Build of SteamOS and Its Translation Layers to Mac

FX Steam Launcher, an independent open-source project on GitHub, runs the ARM64 Steam Frame build of SteamOS on Apple Silicon Macs via a virtual machine, using Proton 11 and FEX for Windows game compatibility. The launcher downloads the official SteamOS image from Valve and handles OS updates, but only supports Apple Silicon Macs on macOS 15 or newer, with the KosmicKrisp translation layer requiring macOS 26 or later. YouTuber ETA Prime tested it on an M4 Max with The Witcher 3, Stellar Blade, and Left 4 Dead 2, seeing over 70 FPS at high settings, with Left 4 Dead 2 past 200.