It's all games written for windows, but at this point valve bankrolls proton and wine development so heavily it might as well be an in-house product. Valve woul

It's all games written for windows, but at this point valve bankrolls proton and wine development so heavily it might as well be an in-house product. Valve would like all games to be written for Linux (case in point: Steam machines) but the reality is that game devs are slow to adapt and desktop gaming is still largely done on PC. With that in mind, proton _is_ the killer app.