Department of Computer Science, University of Kaiserslauter n P .O. Box 3049, W - 6750 Kaiserslautern Germany

P ANDA is a run-time package based on a very small operating system kernel which supports distributed applications written in C++. It provides powerful abstractions such as very ef ficient user -level threads, a uniform global address space, object and thread mobility , garbage collection, and persistent objects. The paper discusses the design ration- ales underlying the P ANDA system. The fundamental features of P ANDA are surveyed, and their implementation in the current prototype environment is outlined.