This speech describes the goals of the MAI project (MetaOPAC Azalai Italiano). MAI derives from the collaboration of AIB, Associazione Italiana Biblioteche, and CILEA, Consorzio Interuniversitario per l'Elaborazione Automatica. The main goal of MAI is the realization of virtual bibliographic specialized catalogues. In this speech MAI technical and functional characteristics and some of the most important realizations are described.