Apparently Firaxis still hasn't given up on getting pitboss to work. But seeing how GMR works there's no real need for pitboss anyway. You don't need to run a server for it, so in that aspect it's even better than pitboss. Not with simultaneous moves though, unfortunately.
As for Linux: the game has Steamplay, Steam pushes for Linux, so hey, who knows what might be coming up. There has to be a good reason they don't have pitboss working, and that reason has to be Linux
