While computer simulation packages are commonly available, manysimulations are still written without the use of existing software. Thisfact is primarily because current software simulation technology has someserious limitations. For example, current packages rely on cartoon-like,predefined, 2-dimensional graphical representations and are difficult toextend. Further, the packages do not take advantage of sophisticatedsimulation software developed by academic and government researchers nor dothey allow simulations to be displayed on workstations and executed onsupercomputers (heterogeneous computing). The goal of this proposal is tocreate an extensible simulation environment using 2-dimensional and3-dimensional visualizations. The environment would operate on user-definedor existing applications. Phase I would define and prototype avisualization language that allows the rapid construction of simulationvisual layouts. Phase II would explore the technology necessary tointegrate user-defined software and to support heterogeneous computing.Phase III would concentrate on developing a graphical interface to thesimulation environment and attracting commercial support.