Pierre-Loup Griffais, writing for the Steam Community:
So, two years ago, we started an effort to improve the quality and performance of Windows compatibility solutions for Steam games.
[…]As a result of this work, today we are releasing the Beta of a new and improved version of Steam Play to all Linux users! It includes a modified distribution of Wine, called Proton, to provide compatibility with Windows game titles.
This is bringing Linux support to a multitude of games that are only provided for the Windows platform currently. It’s a beta for now and there’s only a dozen or so games currently whitelisted, but you can start any of your own Windows games up with an override to see what they’re like.
I can see this has a long way to go, but Valve should be commended for their efforts here. Linux has a really devout user base, may of whom likely have Windows computers or dual boot setups just to run a smattering of their favourite titles. Check out the detailed post here.