This article describes the University of California MELVYL(R)¹ system and its implementation of the Z39.50 information retrieval protocol. It describes the protocol itself and the implementation of it that is being done as part of the UC MELVYL system. It also discusses some of the open issues involving the protocol as well as some of the activities that are going on in the implementation arena. Finally it attempts to discuss some of the implications of the Z39.50 protocol for the library and information world.