Apple's Macs have traditionally packed powerful Intel CPUs and NVIDIA GPUs.  One would think that they would prove an ideal home for PC games; but in reality they have only received a limited selection of high-profile ports.  That's mainly because most PC games rely on Direct X, a proprietary Microsoft API.  Macs use OpenGL instead, necessitating a port.  This is just one of multiple API-level differences between Windows gaming and Mac gaming.

Fortunately for Mac gamers, the big powers are finally showing them some love.  Valve is beta testing Mac versions of its Steam content delivery system and Source game engine and will soon be releasing a variety of games to the platform, including Half Life 2, Left 4 Dead 2, and Team Fortress 2.

Valve just announced this week that it would be releasing the betas to the public on May 12.

Blizzard – makers of StarCraft, Diablo, and Warcraft – has a long relationship with Apple, but hasn't been tossing as many titles their way of late.  However, Blizzard is stepping up its Mac efforts as well.  Blizzard just released a beta version of the upcoming StarCraft II for Mac.

Mac players can snag the test release for free at Battle.net, but they must already be in the beta test program to get it.  

In non-Mac StarCraft II news, the upcoming title has received a new map editor patch, that allows users greater flexibility in crafting custom levels and mods.  A couple of users are already showing off their handiwork, crafting a Diablo clone and a Kart racing game with it.