The number of ontologies being built and made available for reuse has increased steadily in the last few years. While being a foundation for the Semantic Web, this new environment where ontologies are shared and interlinked online also poses new challenges; fostering thus a number of research projects aiming to understand, amongst others, ontology reuse, storage, publication, retrieval and modularization. Indeed, the growing number of online ontologies makes the availability of ontology repositories, in which ontology practitioners can easily find, select and retrieve reusable components, a crucial issue. The recent emergence of several ontology repository systems is a further sign of this. However, in order for these systems to be successful, it is necessary to provide a forum for researchers and developers to discuss features and exchange ideas on the realization of ontology repositories in general and to consider explicitly their role in the ontology lifecycle. In addition, it is now critical to achieve interoperability between ontology repositories, through common interfaces, standard metadata formats, etc. ORES10 intends to provide such a forum.