FX Steam Launcher brings SteamOS to Apple Silicon Macs

A modding project called FX Steam Launcher allows Windows games to run on Apple Mac devices using Valve's SteamOS. The project uses the ARM64 version of the operating system designed for the Steam Frame VR headset. It runs SteamOS inside a lightweight virtual machine on Hypervisor.framework using libkrun and GPU acceleration via Venus. This setup allows users to run Windows titles through Proton and FEX translation layers while keeping access to macOS.

Image: Club386

DirectX 9, 10, and 11 games are supported via DXVK. DirectX 12 games use VKD3D-Proton, with graphics instructions passing through Mesa Venus, MoltenVK, or KosmicKrisp before reaching Apple's Metal API. However, games that rely on anti-cheat systems blocked by virtual machines will not work. The project requires Apple Silicon Macs running macOS 15 or newer, though KosmicKrisp for DirectX 12_0 games requires macOS 26 or later. Games requiring Shader Model 6.6 or DirectX feature level 12_1 are unsupported.

In tests on a MacBook Pro with an M4 Max, YouTuber ETA Prime reported running several games. Stellar Blade reached over 70 fps at 800p on High settings, Fallout 4 stayed at a 60 fps cap at 1080p on Medium, and GTA IV hit approximately 100 fps at 1080p on Medium. The Witcher 3 ran at 70 fps at 1080p on High, though the tester noted issues rendering trees. Total system RAM usage during these tests reached 27GB, with roughly 19GB allocated to the virtual machine.