ValveSoftware/Proton

Choose this fork if you want a CachyOS-oriented Proton with extra user-facing knobs and docs. Stick with upstream Proton if you want the least-divergent, fastest path to Valve's latest fixes and defaults.

Choose this fork if you want a living development branch with custom compatibility experiments, broader input/locale work, and willingness to trade stability for tuning. Stick with upstream Proton if you want the most conservative, well-integrated option.

Choose this fork if you need a custom-maintained Proton line with extra integration and patch management, especially around OpenXR and bespoke compatibility fixes. Avoid it if you just want the most stable, lowest-maintenance Proton experience from Valve.

Choose this fork only if you specifically need Gallium Nine-era customization. For general Proton use, upstream is the better choice because this fork is far behind and likely misses many years of compatibility work.

Choose this fork if you specifically need its Reflex/upscaler-oriented customization or game-targeted patches. Choose upstream Proton if you want the most current, broadly maintained compatibility baseline.

Choose this fork only if speedhack support is the goal and you can tolerate being significantly behind current Proton. For broad compatibility, stability, or low-maintenance use, upstream Proton is the better default.

Prefer upstream Proton unless you specifically need an older 4.13-era fork with the `PROTON_NO_FSYNC` option or the environment-handling change. This fork looks useful for narrow compatibility experiments, but it is too stale for general adoption.

Choose this fork if your priority is compatibility experimentation and broad custom fixes, especially around Wine, OpenXR, Wayland, FEX, or specific problem games. Avoid it if you want the closest thing to Valve’s upstream Proton with the smallest regression surface.

Choose this fork only if you need its specific Steamworks/VR/OpenXR or game-level patches; otherwise upstream Proton is the safer default because this fork is materially stale and likely missing newer compatibility fixes.