This is an edited volume based on the 2007 Conference on Metadata and Semantics Research (MTSR), now in its second meeting. Metadata research is a pluri-disciplinary field that encompasses all aspects of the definition, creation, assessment, management and use of metadata. The volume brings together world class leaders to contribute their research and up-to-date information on metadata and semantics applied to library management, e-commerce, e-business, information science and librarianship, to name a few. The book is designed for a professional audience composed of researchers and practitioners in industry.