iWay Service Manager (iSM) is a fully featured message analysis and execution system. In iWay Service Manager, applications are defined by the configuration of actions to be taken in response to any specific message that arrives. As is the case with any generalized system, the set of supplied actions may not exactly match the needs of your specific application. iWay Service Manager is designed to be easy to modify using custom programming objects to meet specific application requirements. This chapter describes the schematic architecture of the engine, and provides a context for understanding and using the development services that iWay Service Manager supports.