A really powerful game engine used by Epic Games. Very beautiful and popular engine, one of the very best engines out there for video games. It very popular because it supports practically any platform it's put on (PC, XBox, Gamecube, PS2, etc... and even Mac)
A great deal of the gameplay code is written in UnrealScript, a
proprietary scripting language, and as such large parts of the gameplay can be modified without
delving deep into the engine internals. As with other
middleware packages, the Unreal Engine provides various tools to assist with content creation for designers and artists.
It has 3 versions: 1 (1998-2002), 2 (03-06), and 3 (06-future)