This study addresses formal description techniques (FDTs) applicable to distributed systems and communication protocols. It aims to present the state of the art in theory, application, tools and industrialization of FDTs. Among the important features presented are: FDT-based system and protocol engineering; FDT-application to distributed systems; Protocol engineering; Practical experience and case studies. The text comprises the proceedings of the Joint International Conference on Formal Description Techniques for Distributed Systems and Communication Protocols and Protocol Specification, Testing and Verification, sponsored by the International Federation for Information Processing, and held in November 1998, Paris, France. The work is suitable as a secondary text for a graduate-level course on Distributed Systems or Communications, and as a reference for researchers and practitioners in industry.