The Austrian Centre for Parallel Computation (ACPC) is a cooperative research organization founded in 1989 to promote research and education in the field of software for parallel computer systems. The areas in which the ACPC is active include algorithms, languages, compilers, programming environments, and applications for parallel and high-performance computing systems. This volume contains the proceedings of the First International Conference of the ACPC, held in Salzburg, Austria, September 30-October 2, 1991. Authors from 15 countries submitted papers, from which 28 were selected and presented at the conference. They appear in this volume together with 8 invited papers by distinguished researchers.