Steam, as promised, has launched a Mac version of its service bringing with it a new world for Mac users not used to being able to play the latest games on their computer.

The new software, which went live late on Wednesday evening, has launched with 64 games, including Portal, Civilization IV, and the Monkey Island series, although misses out big classic titles such as Half Life and Battlefield 2, much to the annoyance of some gamers.

In an attempt to lure Mac users in, Valve, the company behind Steam, is offering the game "Portal" for free until the 24 May.

Users who've already got a Steam account on a PC can use the same login to access the service on the Mac and games that are available for both platforms will be available for one single price.

Furthermore because your bought games are locked into your account rather than your machine, you're able to access them anywhere with what the company calls SteamPlay, says Valve. 

Have you tried it yet? If so, what games have you downloaded? Let us know in the comments below.