Abstract
This paper discusses PlanetDR, whose architecture supports very large federated educational digital repositories. It is based on the implementation of current open specifications for interoperability (such as IEEE Learning Object Metadata and IMS Digital Repositories Interoperability, in its Edusource Communication Language version), and its integration with the workflow of eLearning production in the context of the Reload Learning Design editor. This integration should support better re-use of resources; some open problems for enhancing further this re-use are also discussed.