Proton is a Valve software creation that provides a “bag-of-tricks” for running games designed for Windows on Linux. Valve’s Proton should not be confused with the swiss privacy provider ProtonAG
In practice, proton is implemented on top of Wine.
GEProton
GloriousEggroll Proton (GEProton) is a customised version of Proton with additional fixes and patches that the Valve version has not yet incorporated. The official way to install GEProton is using the asdf version manager but I have generally found that ProtonUpQT is a nicer way of managing proton versions.