In 2005, a group of scholars decided to start a conference series related to metadata as a concrete research and inquiry discipline, called MTSR (Metadata and Semantics Research conference). The first conference took place completely online in 2005, and the second is being organized as a hybrid (part physical, part on-line) event by the Ionian Academy of Corfu (Ionian University) that will take place in 2007. The conference aims at bringing together researchers and practitioners that share a common interest in metadata, its representation, its semantics and its diverse applications. The contents of this e-book gather together papers selected for further expansion from the first conference and others coming from both an open call and regular submission to the journal, all of them sharing its relation with metadata as an object or technology of interest and their applications to digital libraries and information centres.