Transputers constitute a revolutionary category of microprocessors for parallel processing which have become market leaders in 32-bit RISC architectures. The wide range of applications has caused a multitude of activities of user groups in all major countries, as well as regional activities on four continents. For the first time the collaboration of all these user groups has let to the organization of a world conference: "Transputing '91". This event coincides with the technical disclosure of the new generation of the transputer - H1. The design goals for H1 are to enhance transputer products. The first articles commenting on the H1 development are included in this volume. In total sixty-two contributions by leading experts on the theory and application of transputer technology cover all major areas involved. "Transputing '91" is aimed at those involved with multi-processing architectures and applications.