For search and retrieval of full-text, image, and multimedia information over a heterogeneous network, a non-proprietary standards-based communications protocol is mandatory. In order for the protocol to achieve general acceptance and ubiquity within the rapidly evolving world of distributed information access, it is imperative that the implementation of this protocol be simple and modular, yet rich enough in functionality to meet the growing demands of the information age.
This paper describes implementation experience with the ANSI/NISO Z39.50-1995 information retrieval protocol as the communications protocol of choice for distributed information access. The requirement for simplicity is achieved with an implementation of a baseline set of Z39.50 services. The described base-level functionality is sufficient to demonstrate interoperable search and retrieval functionality with a number of other Z39.50 implementations. The requirement for modularity and richness in function is achieved through the incremental implementation of features such as Generic Record Syntax, Element Set Specification, and the Explain Facility.