What is Proton used for?

Proton is Valve's Steam Play compatibility tool that uses Wine to run Windows-only games on Linux. It is a good fit for playing Windows games on Linux or Steam Deck and customizing Wine versions per game.

Is Proton open source?

Yes. Proton is open source under a custom licence. Its source code is on GitHub at ValveSoftware/Proton and is written mainly in C++.

Yes. Proton is open source, so the software itself is free to use under the terms of its own licence.

Can I self-host Proton?

Yes. Proton can be self-hosted on your own server or infrastructure; there is no official hosted version.

What are some alternatives to Proton?

Similar open-source tools in the Games & Emulation category include Heroic Games Launcher, Lutris and Sunshine. SaaS products in the same category include BacklogShuffle, BlueStacks and Counter-Strike 2.

Is Proton actively maintained?

Yes. The most recent commit to Proton was on 2 October 2026. The project has 33k stars on GitHub.

Proton: open-source games & emulation

About Proton

Proton is a compatibility tool for the Steam client that lets games available only for Windows run on Linux. It uses Wine to do this, along with additional components bundled by Valve. Most people never touch the source, because the Steam client supplies Proton itself, and the README directs ordinary users to that built-in version.

The repository exists so advanced users can alter Proton, for example to pair a game with another Wine release than the default. You clone the source with its submodules, change any sub-component such as the wine directory, and build most of it inside the Proton SDK container. The build needs Docker or Podman, and the maintainers recommend a rootless Podman setup. A changelog is kept on the project wiki. The repository metadata lists the license as Other.

Key features

Runs Windows games on Linux through Steam
Built on Wine with extra components
Bundled with the Steam client
Source buildable in a Proton SDK container
Swap in a different Wine for specific titles
Changelog maintained on the project wiki

Good fit for

→Playing Windows games on Linux or Steam Deck
→Customizing Wine versions per game

Built with: C++
Tags: steam; wine; gaming; linux; compatibility-layer; windows-games; valve; proton

Proton: questions and answers

What is Proton used for?: Proton is Valve's Steam Play compatibility tool that uses Wine to run Windows-only games on Linux. It is a good fit for playing Windows games on Linux or Steam Deck and customizing Wine versions per game.
Is Proton open source?: Yes. Proton is open source under a custom licence. Its source code is on GitHub at ValveSoftware/Proton and is written mainly in C++.
Is Proton free?: Yes. Proton is open source, so the software itself is free to use under the terms of its own licence.
Can I self-host Proton?: Yes. Proton can be self-hosted on your own server or infrastructure; there is no official hosted version.
What are some alternatives to Proton?: Similar open-source tools in the Games & Emulation category include Heroic Games Launcher, Lutris and Sunshine. SaaS products in the same category include BacklogShuffle, BlueStacks and Counter-Strike 2.
Is Proton actively maintained?: Yes. The most recent commit to Proton was on 2 October 2026. The project has 33k stars on GitHub.