5. Architecture
MediBook integrates the access to different information systems, managed at different locations. This scenario requires a broker oriented middleware, to combine the metadata descriptions of the physical resources with the formal representation of the specific domain. With this architecture users have a single point of access not only to different types of informations, but also to information which is managed and stored at different places. Figure 1 gives an over- view of the MediBook architecture. Retrieval, tagging and composing requests from all clients are passed to the bro- ker middleware which is responsible to select and query the appropriate database.