CDC WONDER is an information management architecture designed for public health. It provides access to information and communications without the user's needing to know the location of data or communication pathways and mechanisms. CDC WONDER users have access to extractions from some 40 databases; electronic mail (e-mail); and surveillance data processing. System components include the Remote Client, the Communications Server, the Queue Managers, and Data Servers and Process Servers. The Remote Client software resides in the user's machine; other components are at the Centers for Disease Control and Prevention (CDC). The Remote Client, the Communications Server, and the Applications Server provide access to the information and functions in the Data Servers and Process Servers. The system architecture is based on cooperative processing, and components are coupled via pure message passing, using several protocols. This architecture allows flexibility in the choice of hardware and software. One system limitation is that final results from some subsystems are obtained slowly. Although designed for public health, CDC WONDER could be useful for other disciplines that need flexible, integrated information exchange.