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

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.