This paper presents a four-faceted framework for distributed applications that use worldwide networks connecting large numbers of people, software tools, monitoring instruments, and control devices. We describe a class of applications, identify requirements for a framework that supports these applications, and propose a design fulfilling those requirements. We discuss some initial experiences using the framework, and compare our design with other approaches. ∗The Caltech Infospheres Project is sponsored by the Air Force Office of Scientific Research under grant AFOSR F49620-941-0244, by the CISE directorate of the National Science Foundation under Problem Solving Environments grant CCR-9527130, by the Center for Research in Parallel Computing under grant NSF CCR-9120008, by the Advanced Research Projects Agency, and by Parasoft, Inc. and Novell, Inc. This paper is partially based upon work supported under a National Science Foundation Graduate Fellowship. 1
K. Mani Chandy, Joseph Kiniry, Adam Rifkin, Daniel