The 69.2MB update was released by Apple Tuesday afternoon. It is available from the company's support site, or via Software Update. It requires Mac OS X 10.6.4.
According to Apple, the software update contains performance and stability fixes for graphics applications, including fixes that:
address frame rate issues occurring in Portal and Team Fortress 2 on certain Macs
resolve an issue that could cause aperture 3 or StarCraft II to unexpectedly quit or become unresponsive.
The update addresses framerate issues on the titles Portal and Team Fortress 2 for the late 2009 and mid 2010 iMac and Mac mini; early 2009 Mac Pro; early 2009 and mid 2010 MacBook; and mid-2010 MacBook Pro 15- and 17-inch models.
The update also resolves an image corruption issue that may occur when disconnecting and reconnecting external displays while the system is running.
Valve, the maker of Portal, Team Fortress 2 and the Steam gaming client for Mac, said in June that it was working with Apple to improve the performance of games running in Mac OS X. The company said that improved drivers from Apple would have the greatest impact on performance.
"We are making a lot of progress identifying specific issues that need work inside the game and inside OpenGL and drivers," Rob Barris of Valve said at the time. "Apple, ATI and Nvidia are all involved."