At last, Valve has rolled out Steam for the Mac. Valve initially only said that Left 4 Dead, Left 4 Dead 2, and the Orange Box games would get Mac ports at first, and so far only Portal has hit the Mac side of the games service. Even without the Valve-powered goodness, Steam’s Mac library has hit the ground running with a surprising number of Mac ports available from the start. Besides Portal, Mac users can download Tales of Monkey Island, Sam & Max: The Devil’s Playhouse, Braid, Torchlight, Civilization IV, and several dozen other games.

All Mac-compatible games on Steam are available through SteamPlay, a system that lets users play their games on either PCs or Macs. If you buy a Mac game on Steam and download it to your iMac, you can download the same game to your PC without having to pay again. Likewise, if you get a game on your PC and it has a Mac port, you can download it to your Mac without shelling out extra money. Way to show some foresight, Valve.