Immersive, interactive applications grouped under the concept of Immersipresence require on-line processing and mixing of multimedia data streams and structures. One critical issue seldom addressed is the integration of different solutions to technical challenges, developed independently in separate fields, into working systems, that operate under hard performance constraints. In order to realize the Immersipresence vision, a consistent, generic approach to system integration is needed, that is adapted to the constraints of research development. This paper introduces SAI, a new software architecture model for designing, analyzing and implementing applications performing distributed, asynchronous parallel processing of generic data streams. SAI provides a universal framework for the distributed implementation of algorithms and their easy integration into complex systems that exhibit desirable software engineering qualities such as efficiency, scalability, extensibility, reusability and interoperability. The SAI architectural style and its properties are described. The use of SAI and of its supporting open source middleware (MFSM) is illustrated with integrated, distributed interactive systems.