This book contains collected lectures given at the 1990 ALCOM Spring School of Parallel Computation. The motivation for the school was to provide an introduction for graduate students to topics at the leading edge of research in this very active area of computer science. Topics covered include PRAM algorithmics, general purpose computation, systolic and distributed algorithms, distributed memory models, as well as issues from practical parallel computation. The papers by some of the leading figures in this field have been carefully edited to make a coherent and unique introduction to the state of the art in concurrent computing.