This study is meant for institutional repository managers, service providers, repository software developers and generally, all players taking an active part in the creation of the digital repository infrastructure for e-research and e-learning. It reviews the current standards, protocols and applications in the domain of digital repositories. Special attention is being paid to the interoperability of repositories to enhance the exchange of data in repositories. It aims to stimulate discussion about these topics and supports initiatives for the integration of and, where needed, development of new standards. The authors also take a look at the nearby future: which steps have to be taken now in order to comply with future demands? This title is available in the OAPEN Library - http://www.oapen.org.