QuArK was originally envisaged as having a map editor and a model editor. The latter hasn't been quite finished yet, but originally Andy Vincent was working hard on it, and at the moment cdunde is.

Files that are providing facilities for both editors are usually prefixed with q- (qdictionnary.py, qkeys.py, etc.), those for the map editor with map- (mapeditor.py, mapentities.py), and those for the mdel editor with mdl-. These are however just conventions, and not always adhered to.