Valve's been a dominant force in the PC gaming community for years now and announced in March that it was going to extend the Steam gaming platform onto Apple's OS X operating system. Yesterday, the company did just that. Upon launch, Steam for Mac had 63 games that users could play.

　　In a bid to jump-start the platform, Valve is also offering Portal for free until May 24. The majority of games currently available fall into the casual department, but there are a few major titles in the list: Civilization IV, the Sam & Max series, World of Goo, and on the somewhat dated side - Call of Duty and Call of Duty 2. On the casual side Valve included Peggle Deluxe, Zuma Deluxe, and many others.

　　Being the gamers that we are, we had to test how Steam functioned on OS X. We loaded up Torchlight and found that Cloud game saves from the PC side did not sync up with the Mac version of the game. Of course, we also don't imagine this particular scenario being a thorn in many a gamer's side.

　　We fired up Portal for some benchmarking and came away a bit disappointed. First off, we noticed that HDR rendering was not an option on the Mac version. Overall performance also took quite a hit when compared to Portal running under Windows 7 via Boot Camp. With medium settings, the Mac version trailed by 25 percent, and when we switched over to higher quality settings, the gap widened to 40 percent. It's difficult to give a reason for the slowdown, but we're going to guess that things can only get better from here.

　　Test System: MacBook Pro - Core 2 Duo 2.4GHz, 2GB DDR2 RAM, Nvidia GeForce 8600M GT.