Preface to the Online Edition

This online edition of Digital Libraries is an updated version of the book of the same name published by the M.I.T. Press in January 2000. I am extremely grateful to the press for giving me permission to place it online even while the book is still in print.

The field of Digital Libraries is moving rapidly. Most of this book was written in 1998 and many sections are now seriously out of date. In particular:

• In the few years since the book was written, there have been some major developments. Important topics that need to be updated or included for the first time include the emergence of XML, the dominance of Google, reference linking, the Internet Archive, the Open Archives Initiative, and many more.

• Numerous details need to be brought up to date.

• A few projects have come to an end and a few topics have proved to be less important than expected. They need to be deleted or give less emphasis.

• The book does not have a bibliography, because, only a few years ago, nobody had confidence in the longevity of URLs. Now it is clear that many online collections are managed for the long term and can be cited with confidence.

• Our understanding has developed. In some aspects, uncertainties have been resolved; in others the complexities seem to have grown. There is less need to be an advocate for digital libraries.

Despite being out of date in these ways, the major themes and much of the material remains valuable. In particular, the importance of understanding the human and social context while carrying out technical work remains the heart of all work in digital libraries.

William Arms
June 2005