I'm pretty sure that's Aspyr Media's (https://www.aspyr.com/about https://www.aspyr.com/about) business model. At least, I know they're the ones who ported Fire

I'm pretty sure that's Aspyr Media's (https://www.aspyr.com/about https://www.aspyr.com/about) business model. At least, I know they're the ones who ported Fireaxis' Civilization games to OSX and Linux.