Federation of distributed and collaborative Repositories and its application on Science Learning objects

The paper deals with the design and the implementation of a federation of collaborative repositories for learning objects management based on an efficient mechanism of filing and retrieving distributed knowledge. The proposed federation is meant to deal with a large variety of different contents though the discussed prototype implementation is concerned with scientific and educational subjects in particular. The existing hierarchic architecture has been modified into a peer network model. Both the pure peer network and the hybrid topologies are tested to evaluate their scalability with both geographical extension and volume of contents. Additional elements of evaluation have been the capability of enhancing collaboration and fault tolerance.