Epic Games has released September 2011 UDK Beta, a new beta of its Unreal Engine 3 Development Kit that has support for OS X. This paves the way for games built using the 3D game engine to appear on the Mac.
Unreal Engine is the 3D game engine behind Gears of War series and Unreal Tournament 3 on the console. It was also adopted by other major gaming companies. Unreal Engine has been made available for iOS for more than two years. Epic Games’ Infinity Blade, based on Unreal Engine, was an instant hit on iOS. Unreal Engine Development Kit is free for non-commercial use and you can download it from udk.com website.