Why are there so many different Proton versions? Proton 8, Proton 9, Experimental, GE-Proton

Are you confused on why there's many different versions of Valve's Proton? The compatibility layer that runs Windows games on Linux / SteamOS and Steam Deck. Here's a little guide on what it all means.

Valve Official

There's a few versions of the official Proton now so here's a brief explanation:

• Proton Experimental - Gets regular updates with features and fixes not ready for everyone and can include some breaking changes that need new GPU driver versions. Think of it like a staging area to test what Valve think will be ready for everyone sometime soon.
• Proton Bleeding Edge - a constantly updated opt-in Beta for Proton Experimental that has all the changes as they happen. It will be highly unstable. This is really not recommended for any normal user.
• Proton Hotfix - A few extra fixes for specific games when needed.

Then there's also the numbered versions, which make up the "stable" releases, which is what most people would be using. Usually the latest release will replace the one before:

• Proton 9.0-x - The latest in the stable series. Released May, 2024.
• Proton 8.0-x - The previous stable version. Released April, 2023.
• There's also the Proton 7.0, Proton 6.3 series, Proton 5.0 series, Proton 4.2 and so on.

So why so many different versions? Each major release brings in tons of upgrades (a lot from Wine, which Proton is based on) and so they could end up breaking various games. Valve keep the older numbered versions around in case they work better for specific games.

All official Valve Proton can be downloaded directly in your Steam Library on a Linux system (Steam Deck / SteamOS / Linux desktop).

Community Builds

You also have some community-made versions of Proton, that offer things Valve don't (or legally cannot). These are not supported by Valve.

GE-Proton: made by Thomas "GloriousEggroll" Crider. This is often updated faster than the official Proton, with extra fixes including these (noted from the GitHub page):

• Additional media foundation patches for better video playback support
• AMD FSR patches added directly to fullscreen hack that can be toggled with WINE_FULLSCREEN_FSR=1
• FSR Fake resolution patch details here
• Nvidia CUDA support for PhysX and NVAPI
• Raw input mouse support
• 'protonfixes' system -- this is an automated system that applies per-game fixes (such as winetricks, envvars, EAC workarounds, overrides, etc).
• Various upstream WINE patches backported
• Various wine-staging patches applied as they become needed

Proton-Sarek: A custom Proton build with DXVK-Sarek for users with GPUs that support Vulkan 1.1+ but not Vulkan 1.3, or for those with non-Vulkan support who want a plug-and-play option featuring personal patches. To put it real simply: if you have an old GPU this might give you better compatibility.