Scholarship at Penn Libraries

Document Type

Technical Report

Date of this Version

January 2003


This report provides an overview of a diverse set of more than thirty digital library aggregation services, organizes them into functional clusters, and then evaluates them more fully from the perspective of an informed user. Most of the services under review rely wholly or partially on the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH), although some of them predate its inception and a few use predominantly Z39.50 protocols. In the opening section of this report, each service is annotated with its organizational affiliation, subject coverage, function, audience, status, and size. Critical issues surrounding each of these elements are presented in order to provide the reader with an appreciation of the nuances inherent in seemingly straightforward factual information, such as "audience" or "size." Each service is then grouped into one of five functional clusters:

• open access e-print archives and servers;

• cross-archive search services and aggregators;

• from digital collections to digital library environments;

• from peer-reviewed "referratories" to portal services;

• specialized search engines.


Copyright 2005 by the Digital Library Federation, Council on Library and Information Resources. No part of this publication can be reproduced or transcribed in any form without permission of the publisher.
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NOTE: At the time of publication, the author Martha L. Brogan was an Independent Digital Library Researcher and Consultant. Currently June 2007, she is Associate University Librarian for Collection Development and Management at the University of Pennsylvania.



Date Posted: 06 June 2007