This collection of fourteen papers describes the Cooperative Online Resource Catalog (CORC) project, a pioneering collaborative system hosted by OCLC to improve cataloging productivity and facilitate the discovery of high-quality information resources on the web. The essays provide a blend of theoretical and practical approaches to metadata creation using Dublin Core and CORC system tools. Authors bring a variety of perspectives to bear including those of the CORC founders, researchers, developers, observers, library practitioners and managers.