ZING Initiative at LOC: v1.0 SRW & CQL

The ZING Initiative (Z39.50 International Next Generation), under the auspices of the Z39.50 Maintenance Agency at the Library of Congress, is pleased to announce Version 1.0 of SRW and CQL.

SRW ("Search/Retrieve for the Web") is a web-service-based protocol which aims to integrate access across networked resources, and to promote interoperability between distributed databases by providing a common platform. The underpinnings of the protocol are formed by bringing together more than 20 years experience from the collective implementers of the Z39.50 protocol with recent developments in the web-technologies arena. SRW features both SOAP and URL-based access mechanisms (SRW and SRU respectively) to provide for a wide range of possible clients. It uses CQL, the Common Query Language, which provides a powerful yet intuitive means of formulating searches. The protocol mandates the use of open and industry-supported standards XML and XML Schema, and where appropriate, Xpath and SOAP.

The SRW Initiative recognizes the importance of Z39.50 (as currently defined and deployed) for business communication, and focuses on getting information to the user. SRW provides semantics for searching databases containing metadata and objects, both text and non-text. Building on Z39.50 semantics enables the creation of gateways to existing Z39.50 systems while reducing the barriers to new information providers, allowing them to make their resources available via a standard search and retrieve service.

SRW, SRU, and CQL have been developed by an international team, minimizing cross-language pitfalls and other potential internationalization problems.

The ZING, SRW, and CQL home pages are at:
http://www.loc.gov/srw, and
The Z39.50 Maintenance Agency home page is at

The SRW and CQL version 1.0 specifications will remain stable for a six- to nine-month implementation-experience period. During this period developers are encouraged to implement the specification (see the implementors page at http://www.loc.gov/srw/implementors.html), join the list of implementors, participate in interoperability testing, and help develop the next version, 1.1. Please direct questions, comments, and suggestions to z3950@loc.gov.