This text aims to describe the many developments revolutionizing library services and leading to a fundamental rethinking of the role of the library in society. The way ahead for the profession is generally seen as a practical blend of traditional and electronic materials often referred to as the hybrid library. This study offers a structured digest of research and development on hybrid libraries, within a clear model that spells out in accessible language how traditional and electronic sources can co-exist in the library of the future. It examines the changes brought about by the widespread availability of digital information and the ease with which users can find information for themselves on the Internet and the World Wide Web, and asks why we still need libraries. The author argues that, despite all the advances in direct user access to information, libraries still have a major role to play - in organizing information sources, arranging access to collections, helping users to find and use information, arranging training and providing centres where people can access the tools needed for effective use of information in all walks of life. But the way they fulfil these roles is changing and libraries must play a full part in bringing together regional, national and international information resources in ways that enable users to exploit them to the full. Libraries are also considered within the broader context of the networked information world, taking account of technological advances and drawing on a range of international research and development experience. Specific topics covered include: the importance of the library as broker; the infrastructures necessary for operation in networked environments; authentication of users and information seeking behaviour; the role of metadata; new information objects, including multimedia; knowledge management, capture and retrieval; issues of retrieval and display, including content-based retrieval; preservation and electronic legal deposit; security, accessibility and disability issues; and copyright in networked environments. Librarians of the future, Brophy argues, will need to see themselves in new roles, and will need advice and training in order to become new style information experts. This text looks at the contribution made by the library to modern society and suggests a practical agenda of issues for library professionals to tackle. It should be useful reading both for established practitioners and LIS students.