Intermediaries: An approach to manipulating information streams

Information flows all around us all the time. Whether on computer networks, on telephone lines, or within the wiring of everyday devices such as coffeemakers or gas pumps, data are constantly being transmitted from one place to another. Much of the time, such data flow directly between information producers and information consumers. Sometimes, however, intermediary processes stand in the way of a simple data flow, for instance to monitor traffic, to bridge between incompatible communication streams, or to customize or extend the functions that are natively available on a stream. Intermediaries can turn ordinary information streams into smart streams that enhance the quality of communication. Because information flows are now everywhere, there is a new opportunity for taking advantage of intermediary computation, but general principles and approaches have not yet been developed. This paper provides an introduction to the intermediary approach, describes an implemented Web intermediary framework and applications, and proposes extending intermediaries to other information streams.