Parallel computer architectures are now being used in applications ranging from image analysis to quantum mechanics. However, their use poses serious problems and requires the development of new techniques and tools. This book is a collection of the papers presented at a workshop on major research activity, held at the University of Erlangen-Nurnberg and the Technical University of Munich. The book is divided into five main parts: hardware aspects of multiprocessor systems; the performance of parallel systems; - architectures and tools for parallelization; - modelling techniques; and applications of parallel systems.