ANSI Z39.50 Z39.50 <networking, standard> Information Retrieval Service Definition and Protocol Specification for Library Applications, officially known as ANSI/NISO Z39.50-1992, and ANSI/NISO Z39.50-1995. This {standard}, used by {WAIS}, specifies an {OSI} {application layer} service to allow an application on one computer to query a {database} on another. Z39.50 is used in libraries and for searching some databases on the Internet. The US Library of Congress (http://lcweb.loc.gov/z3950/agency/) is the official maintanence agency for Z39.50. {Index Data}, a Danish company, have released a lot of Z39.50 code. Their {website} explains the relevant {ISO} {standards} and how they are amicably converging in Z39.50 version 4.0. Overview (http://nlc-bnc.ca/ifla/VI/5/op/udtop3.htm). Z39.50 resources (http://lamp.cs.utas.edu.au/net.html#Z3950). (1996-07-22)