Graphical user interfaces (GUIs) are defining what the interface to a program should look like. Unfortunately for programmers who need to use three-dimensional graphics found in environments like PHIGS, there is no convenient way the to use the features found in existing GUI's. This thesis describes the implementation of an interface framework running totally under PHIGS. The framework is designed using object-oriented principles and is coded in C++. The tools provided by the interface emulate the look and feel of the objects found in Motif. The interface is designed in such a way that new objects (such as windows and menu items) can be added in the future without modification to existing code. This flexibility allows programmers to specialize interfaces for their programs while maintaining complete compatibility with the base code. This also allows the framework to emulate other GUIs (such as OS/2 or Macintosh) in addition to Motif. The interface software is therefore referred to as an interface framework rather than a tool kit. The windows and menu items provided in this implementation are samples of the objects that can be created with the framework. / Master of Science