This book constitutes the refereed proceedings of the 5th International Workshop on Interactive Distributed Multimedia Systems and Telecommunication Services, IDMS'98, held in Oslo, Norway, in September 1998.The 23 revised full papers presented were carefully selected from a total of 68 submissions. Also included are seven position statements. The book is divided into topical sections on distributed multimedia applications; platforms for collaborative systems; MPEG; coding for WWW, wireless, and mobile environments; QoS and user aspects; flow control, congestion control, and multimedia streams; multimedia servers, documents, and authoring; and storage servers.