Proton is a compatibility layer that allows Windows software (primarily video games) to run on Linux-based operating systems.

[2] It is a collection of software and libraries combined with a patched version of Wine to improve performance and compatibility with Windows games.

[4] Upon release, Valve announced a list of 27 games that were tested and certified to perform like their native Windows counterparts without requiring end-user tweaking.

[6] Being a fork of Wine, Proton maintains very similar compatibility with Windows applications as its upstream counterpart.

The user can optionally force use of Proton for a specific game, even if a Linux version already exists.

ProtonDB is an unofficial community website that collects and displays crowdsourced data describing the compatibility of a given title with Proton, on a rating scale from "Borked" (doesn't work) to "Platinum" (works perfectly).

[9][10] The site is inspired by the WineHQ AppDB, which also collects and displays crowdsourced compatibility reports and uses a similar rating system.

Supported 27 games, including DOOM (2016), Quake, and Final Fantasy VI.