The goal of this project is to explore the systems architecture of high-end computers to be built a decade from now. A proposed architecture that combines COMA and NUMA designs is being used to explore architectural, applications, and compiler issues. Tools used in the study include an execution-driven simulator, an address tracer, state of the art parallelizing compiler and database systems, and many workloads. The architectural issues to be explored include organizations that merge COMA and NUMA coherence, new uses for cache tags, and design of coherence protocols. Software issues include address translation and memory management within the operating system for a simple COMA, new uses of the data replication that occurs for share data in COMA, compilation of parallel code for cache-coherent architectures, and compilation of explicit data transfers in parallel code into instructions for prefetching and forwarding of data.