This thesis investigates the possibility of using the Apple Macintosh to provide a workstation-like interface for UNIX hosts. Problems of UNIX interface development are identified through a study of existing UNIX interface systems. Techniques from some of these are applied in the design and implementation of MPFW- the Macintosh Programming framework for Workstation Interfaces. This system provides communications and graphical interface support for developing application-specific interfaces on the Apple Macintosh. Part of the thesis is devoted to evaluating the programming facilities offered by the Macintosh. Several weaknesses are identified, and mechanisms for redressing these are featured in MPFW to simply interface programming. Pre-emptive multitasking is one such mechanism, and its implementation is described in some detail. Several related support projects are also presented, including a pseudo-terminal server daemon for Berkeley UNIX systems.