The effective computer animation of human figures is an endeavor with a relatively short history. The earliest attempts involved simple geometries and simple animation techniques which failed to yield convincing motions. Within the last decade, both modeling and animation tools have evolved more realistic figures and motions. A large software project has been under development in the University of Pennsylvania Computer Graphics Research Facility since 1982 to create an interactive system which assists an animator or human factors engineer to graphically simulate the task-oriented activities of several human agents. An interactive system called TEMPUS and its high performance successor is outlined which is intended to graphically simulate the task-oriented activities of several: human agents. Besides an anthropometric database, TEMPUS offers multiple constraint-based joint positioning, dynamic simulation, real-time motion playback, a flexible three-dimensional user interface, and hooks for artificial intelligence motion control methods including hierarchical simulation, and natural language specification of movements. The overall organization of this project and some specific components will be discussed.