Unlocking Global Library Catalogs: Your Guide to Finding Functional Z39.50 Targets

The Z39.50 protocol, a veteran in the world of information retrieval, remains a crucial tool for libraries and researchers. It allows different computer systems to communicate and exchange information, primarily bibliographic data. A "Z39.50 target" is essentially a server that hosts a database (like a library catalog) and makes it searchable via this protocol. Finding reliable, working targets is key to leveraging its power for tasks like copy cataloging and federated searching. This guide will illuminate the best resources for discovering active Z39.50 targets and offer insights into their effective use.

Key Insights: Navigating the Z39.50 Landscape

Understand Core Directories: Several key directories like IRSpy, Z-Brary, and lists from KohaSupport and the Library of Congress are your primary resources for finding Z39.50 targets.
Verify and Test: The operational status of Z39.50 targets can change. Always verify connection details and test targets, as some may require specific configurations or authentication.
Protocol Evolution: While Z39.50 is a mature protocol, newer standards like SRU/SRW are emerging. However, Z39.50 remains widely used, especially within library systems.

What is Z39.50 and Why Does It Matter?

A Foundation for Information Exchange

Z39.50 is an ANSI/NISO and ISO standard client-server protocol designed for searching and retrieving information from remote computer databases. Predominantly used by libraries, it enables a Z39.50 client (software on a user's computer or integrated into a library system) to query a Z39.50 target (a server hosting a database) and retrieve records, typically bibliographic records in formats like MARC (Machine-Readable Cataloging).

Its significance lies in interoperability. Before Z39.50, accessing different library catalogs often meant learning multiple, proprietary search interfaces. Z39.50 standardized this process, allowing, for example, a librarian to search numerous catalogs from different institutions using a single interface for tasks like copy cataloging (finding an existing catalog record for an item to copy into their own system) or interlibrary loan requests.

Diagram illustrating the Z39.50 client-server architecture

A general overview of the Z39.50 client-server interaction model.

Core Components for Connection

To connect to a Z39.50 target, you typically need the following information:

Host Address: The domain name or IP address of the server.
Port Number: The network port the Z39.50 service is listening on (commonly port 210, but can vary).
Database Name: The specific database on the server you wish to search (e.g., "voyager", "innopac", "NL").
Search Attributes: Some systems may require specific search attributes or syntax for queries (e.g., using Bib-1 attribute set).
Authentication: Some targets may require credentials (username/password) or IP-based authentication.

Premier Directories for Z39.50 Targets

Your Go-To Resources for Active Servers

Several online directories specialize in listing and, in some cases, testing Z39.50 targets. These are invaluable resources for anyone looking to utilize the protocol.

IRSpy Z39.50 Target Directory (Index Data)

IRSpy is arguably the most comprehensive and frequently updated directory of Z39.50 and SRU/SRW targets globally. It provides detailed information, including server names, network addresses, port numbers, supported search attributes, and, crucially, reliability information based on recent automated tests. This helps users identify targets that are currently operational and assess their interoperability. Examining the "XML" details for an entry can often reveal the date of the last successful test.

Z-Brary: Directory of Z39.50 and SRU Targets

Z-Brary offers a searchable and browsable directory of Z39.50 and SRU targets, often categorized alphabetically by institution or resource name. It collects and maintains a list of known targets, including libraries, union catalogs, and specialized databases, providing essential connection details.

KohaSupport Z39.50 Server Directory

Koha, a popular open-source Integrated Library System (ILS), heavily utilizes Z39.50 for copy cataloging. KohaSupport maintains a curated list of Z39.50 servers that are known to work well with Koha and are frequently used by its community. This list often includes high-quality servers from trusted library sources with practical connection parameters.

Koha ILS interface showing Z39.50 target configuration

Example of Z39.50 target configuration within the Koha Integrated Library System.

Library of Congress Z39.50 Resources

The Library of Congress (LoC) has been a significant proponent and user of Z39.50. Their website provides valuable resources, including their own Z39.50/SRW/SRU server configuration guidelines, which acts as a gateway to their extensive collections. They also list other Z39.50 resources and directories, often linking to tools like IRSpy for broader target discovery.

ILS Vendor Documentation (e.g., Evergreen, Ex Libris)

Documentation for various Integrated Library Systems, such as Evergreen or Ex Libris products (Alma, Voyager), often includes sections on configuring Z39.50 targets. These guides might list recommended targets or point to the major directories mentioned above. For instance, Evergreen's documentation provides examples and explains how to store credentials for Z39.50 servers.

Evergreen ILS Z39.50 credentials storage example

Example from Evergreen ILS documentation on configuring Z39.50 server credentials.

Comparing Z39.50 Target Directories

Feature Overview of Key Resources

The primary directories for Z39.50 targets offer different strengths. The radar chart below provides an opinionated comparison based on factors like the comprehensiveness of listings, frequency of updates, user-friendliness of the interface, availability of reliability metrics for targets, specific focus on Z39.50, and coverage of its successor protocols, SRU/SRW. This can help you decide which directory best suits your needs when searching for viable targets.

Note: The scores in this chart are subjective estimations for illustrative purposes, reflecting general perceptions of these resources.

Examples of Z39.50 Targets

Illustrative Connection Details

Below is a table showcasing examples of Z39.50 targets, often found in the directories mentioned. It's important to verify current availability and specific connection parameters from the source directories, as server status and details can change.

Institution/Service	Host Address	Port	Database Name(s)	Notes/Source
Library of Congress	lx2.loc.gov	210	LCDB	Primary LoC target; check their site for current status.
Appalachian College Association Union Catalog	library.acaweb.org	210	(Often 'Voyager' or not specified)	Listed in KohaSupport directory.
Arapahoe Community College	164.47.45.4	5666	innopac	Listed in KohaSupport directory.
AMICUS (National Library of Canada)	amicus.nlc-bnc.ca	210	NL, Voyageur	Widely listed; supports MARC format.
Auburn University Library	pooh.lib.auburn.edu	7090	voyager	Often cited in ILS documentation.
OhioLINK (e.g., Xavier University)	olc1.ohiolink.edu	210	innopac	Used by many Ohio academic libraries.

This table provides examples; always consult the respective directories for the most current and comprehensive information.

Understanding the Z39.50 Ecosystem

A Mindmap View

The Z39.50 protocol operates within a broader ecosystem involving clients, servers (targets), directories to find these targets, and various use cases. The following mindmap illustrates these interconnected components, providing a visual understanding of how Z39.50 functions and where to find operational targets.

mindmap root["Z39.50 Protocol"] id1["Core Characteristics"] id1a["Client-Server Model"] id1b["Information Retrieval Standard"] id1c["Primarily Library Focused"] id1d["ANSI/NISO & ISO Standard"] id2["Key Components"] id2a["Z39.50 Clients
(e.g., ILS software, MarcEdit)"] id2b["Z39.50 Targets
(Servers hosting databases)"] id3["Finding Z39.50 Targets"] id3a["Online Directories"] id3a1["IRSpy (Index Data)"] id3a2["Z-Brary"] id3a3["KohaSupport Lists"] id3a4["Library of Congress Resources"] id3b["ILS Vendor Documentation"] id4["Essential Connection Info"] id4a["Host Address (IP/Domain)"] id4b["Port Number (e.g., 210)"] id4c["Database Name"] id4d["Search Attributes (Bib-1)"] id4e["Authentication (if required)"] id5["Common Use Cases"] id5a["Copy Cataloging"] id5b["Interlibrary Loan (ILL) Verification"] id5c["Federated Searching"] id5d["Bibliographic Data Exchange"] id6["Evolution & Successors"] id6a["ZING (Z39.50 International: Next Generation)"] id6b["SRU (Search/Retrieve via URL)"] id6c["SRW (Search/Retrieve Web service)"]

This mindmap shows how users, through client applications, connect to Z39.50 targets (servers) using information often found in specialized directories. The protocol facilitates various library operations and, while mature, has influenced successor technologies like SRU/SRW.

Practical Application: Z39.50 in Action

Using Z39.50 for Cataloging in Koha

Many Integrated Library Systems (ILS) provide built-in Z39.50 client functionality. This allows librarians to search external library catalogs directly from their own system to find bibliographic records for items they are adding to their collection (a process known as copy cataloging). The video below demonstrates how Z39.50 is used within the Koha ILS, showcasing the practical steps of configuring targets and importing records. This example highlights the real-world utility of having access to reliable Z39.50 targets.

This video illustrates the process of cataloging using Z39.50 within the Koha Integrated Library System.

Successfully using Z39.50 involves more than just finding a target; it also requires understanding the client software's interface, correctly inputting connection parameters, and knowing how to interpret and utilize the retrieved records. Resources like the video above, along with documentation from ILS vendors and the Z39.50 directories, are essential for mastering these tasks.