When choosing a graphics system for the run-time support component of a User Interface Management System (UIMS) several problems arise. Existing inputloutput models employed by graphics systems lack support for fine grain design control and for defining links between input and output. Furthermore, hardware maintainability is a problem. We have introduced a new inputloutput model, the symmetrical translation model (STM), which solves these problems through extensibility and symmetry. All input and output techniques are implemented by active objects which are specified using a high level notation. This notation allows the temporal and spatial composition of objects. A UIMS is being constructed at our department based upon this model.

Languages based on the event model are widely regarded as expressive and flexible notations for the specification of interactive graphical user interfaces. However, until now, they have only been used to specify and implement the dialogue control component of user interfaces.