Towards an Open Repository Environment

Repositories used to be fairly monolithic systems, with a single object store, a tailored content model, and a dedicated application on top. First steps for searching across repositories (e.g. Z39.50, first drafted in 1988; OAI-PMH for content aggregation, first released 2001) are an exception to this. However, we are still far away from an ”open repository environment“, in which repositories interact on all levels with other agents (e.g. other repositories, added-value services, registries). This paper creates a more fine-grained view on repository federation and analyses existing approaches by decomposing them into a physical, a logical, and a conceptual layer for both the object and the system. Among these attributes, the most evident gap pertains to interaction ”patterns“ between agents. In particular, the notification pattern is more immediate and directed than existing query and harvesting mechanisms, enabling new federation scenarios and laying the grounds for open repository environments. Prototypes of the concepts presented here are being implemented in the scope of the project Dariah, which establishes an e-Infrastructure for the humanities.