Abstract: A User Interface Management System (UIMS) called MIKE that does not use the syntactic specifications found in most UIMSs is described. Instead, MIKE provides a default syntax that is automatically generated from the definition of the semantic commands that the interaction is to support. The default syntax is refined using an interface editor that allows modification of the presentation of the interface. It is shown how active pictures can be created by adding action expressions to the viewports of MIKE's windowing system. The implications of MIKE's command-based dialogue description are discussed in terms of extensible interfaces, device and dialogue-style independence, and system support functions.