This project investigates the power of the synchronous, data- parallel approach to parallel algorithms development. Many numerical and nonnumerical algorithms can be expressed in an elegant fashion using this methodology. This project focuses on C*, a data parallel language development by Thinking Machines Corporation. If C* compilers can be written that allow for the efficient execution of parallel algorithms on the Connection Machine, multicomputers, and shared memory multiprocessors, then there would be a whole class of algorithms for which no reprogramming would be necessary in order to move an application from one parallel architecture to another. Preliminary results are encouraging, and the PIs are in the process of implementing an optimizing C* compiler for hypercube multicomputers. The focus of this project is to build upon earlier successes by improving the efficiency of the compiled programs, implementing an interactive debugger, exploring more data parallel algorithms and the optimization they require, and porting the C* programming environment to different architectures.