A comprehensive survey of distributed file and operating systems presently in existence or of historical interest. It covers the major design issues of distributed systems and allows the reader to understand and compare the different approaches taken. The survey is organized as an encyclopaedia, and each system is independently described. The descriptions of the systems accord with a catalogue of criteria covering the major design issues, such as transparency levels, heterogeneity, security, and availability. Also included in the volume are a list of contact addresses and more than 600 references to the literature.