Valve announced that it’ll bring Steam, Valve's gaming service, and Source, Valve's gaming engine, to Mac. Steam and Valve's library of games including Left 4 Dead 2, Team Fortress 2, Counter-Strike, Portal, and the Half-Life series will be available in April. "Steamworks for the Mac supports all of the Steamworks APIs, and we’ve added a new feature, called “Steam Play,” which allows customers who purchase product for the Mac or Windows to play on other platform free of charge. For e.g., Steam Play, in combination with the Steam Cloud, allows a gamer playing on their work PC to go home and pick up playing the same game at the same point on their home Mac. "We’re treating Mac as a tier-1 platform so all of our future games will release simultaneously on Windows, Mac, and Xbox 360. Updates for Mac will be available simultaneously with Windows updates. Furthermore, Mac and Windows players will be part of same multiplayer universe, sharing servers, lobbies, and so forth. We fully support a heterogeneous mix of servers and clients. The first Mac Steam client will be new generation currently in beta testing on Windows." Portal 2 will be Valve's first simultaneous release for Mac and Windows. "Checking in code produces a PC build and Mac build at same time, automatically, so two platforms are perfectly in lock-step," said Josh Weier. "We're always playing a native version on Mac right alongside PC. This makes it very easy for us and for anyone using Source to do game development for the Mac."