ModSAF uses Motif and X for its graphical user interface (GUI) as well as standard input/output for its command line interpreter. Soar, which previously depended on standard input/output, was enhanced to include an X interface. This enabled Soar, ModSAF, and the SMI to present GUIs to the user while maintaining module independence. Each module opens a separate display connection to the user's console and receives a separate event stream. This design has the drawback that there is contention for screen real-estate due to a proliferation of separate windows.
The SMI GUI currently enables the user to control the simulation speed. This is helpful for speeding up the simulation in ``dead spots'' or slowing down the simulation to observe at a finer grain the changes in state. Additions to the SMI GUI are planned and will provide more dynamic control over ModSAF and the SMI. In addition to the SMI GUI, the ModSAF GUI was enhanced by adding two windows. The first provides orthographic projections of the PVD so that altitude relationships between vehicles may be depicted graphically. The second is a window of vehicle status information that is continually updated to clarify the status of vehicle position, orientation, radar sightings, and weapon employment.
An alternative interface to Soar was developed independently which utilizes standard input/output. This interface, the Soar Development Environment (SDE), runs in Emacs [SDE reference]. This removes the need for separate windows for Soar agents but forces the elimination of the ModSAF command line interpreter. Both Soar interfaces have their uses and Soar developers have not fully committed to one or the other.