# /research/projects/z3950/default.htm

originally: http://www.oclc.org/research/projects/z3950/default.htm

# Z39.50

This term refers to two information standards:

- the International Standard, ISO 23950: "Information Retrieval (Z39.50): Application Service Definition and Protocol Specification"
- the American standard, ANSI/NISO Z39.50.

The Library of Congress is the Maintenance Agency and Registration Authority for both standards, which are essentially the same.

Z39.50 is a computer-to-computer communications protocol designed to support searching and retrieval of information in a distributed network environment.

The Z39.50 standard continues to evolve to meet the changing needs of information creators, providers, and users.

## About

The goal of this work is twofold:

- to continue the advancement of the standard
- to provide consultation on the standard to OCLC and the LIS community.

## Why OCLC is conducting this research and how it helps libraries

- Z39.50 provides the database searching infrastructure for all our products
- Z39.50 supports the discovery and exchange of MARC-21 records between library systems
- Z39.50 is one of the protocols used to search digital repositories

## Resources

- Maintenance agency page
  - http://lcweb.loc.gov/z3950/agency
- Online "brochure" about Z39.50 by Bill Moen
  - http://www.cni.org/pub/NISO/docs/Z39.50-brochure/50.brochure.toc.html

## Research team

- Ralph LeVan (Principal researcher)