UnrealEd

UnrealEd (UEd for short) is the level editor used to create levels for Unreal. It was also used for other games based on the Unreal engine, such as Deus Ex and Lineage II, although it has changed along with the engine for later games. One of the first companies to do this with first person shooters, all Unreal games on the PC had the level editor included for free, and some third party Unreal engine games did the same with an edited and specialized version. This extended the longevity of the games. Amateur level designers could now create their own levels for the game, providing a near endless amount of additional content for the game. In addition, the built-in scripting language called UnrealScript allowed for editors to customize game content.

UnrealEd has a customizable user interface, but the most common is the quad viewports with the top view in the top left, then, moving clockwise, the front view, the side view, and the perspective view. It has a row of buttons along the top pertaining to various options such as save, open, and rebuild, and a series of buttons to the left of the viewports which access editing functions.