A portable and extensible environment for developing interactive applications

A description is given of work on an architecture for the construction of interactive applications. Originally, on Apollo workstations, almost all support for interactive applications was embedded in a single application, the display manager (DM). The original conception of the DM is discussed, covering its advantages and disadvantages. The new user environment architecture and how it maintains the advantages and eliminates the disadvantages of the DM are examined. Two relatively unplanned results of the redesign are considered: the ability to merge the DM with the X window system, and the ability to develop system-independent (portable) tools.<>