Computers and telecommunications networks offer the potential to share data in electronic format. The challenge has been to develop a mechanism that would standardize communication between existing computer systems. NISO responded to this challenge by establishing a Standards Committee in 1979 to work on an information retrieval protocol. This work culminated in Z39.50-1988. Also beginning in the late 1970s funding by the Council on Library Resources (CLR) supported the development of an experimental protocol as part of the Linked System Project (LSP) for searching bibliographic databases and transferring records among the Library of Congress, the Online Computer Library Center (OCLC), the Research Libraries Group (RLG), and the Washington (now Western) Library Network (WLN). This Linked Systems Protocol laid the groundwork for the Z39.50 protocol.
Shortly after the approval of the standard in 1988, a group of Z39.50 implementors began work to enhance and expand the utility of the standard. NISO balloted a revised version of Z39.50 in 1992. Continuing development of the standard by implementors has resulted in the third version of the standard (Draft Version 3).
Work in the ISO on information retrieval standards resulted in ISO approval in 1991 of two International Standards that are companions to Z39.50: ISO 10162, Search and Retrieve Application Service Definition and ISO 10163-1, Search and Retrieve Protocol Specification. ANSI/NISO Z39.50-1992 harmonized the U.S. standard and the international standards so that the U.S. standard became a compatible superset of the International Standards. In early 1994, international standards developers made a crucial decision to begin the process of adopting Z39.50 as the International Standard. No longer will there be different national and international standards that must be harmonized. Rather, Z39.50 will provide the basis for the International Standard for information retrieval.