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Building multiuser interactive multimedia environments at Mitsubishi Electric Research Laboratories (MERL) is a highly interdisciplinary activity, which involves the efforts of more than a dozen members of the laboratory. This report describes this research at three levels. At the bottom, supporting everything, are high-speed networks. On top of networks, we have built a piece ofmiddlewarecalled Spline. Finally, Diamond Park is an experimental environment we are building using Spline.

Future large distributed systems will be made by interconnecting highly autonomous subsystems, rather than by building ever more elaborate complexes which attempt to provide a single system image transparent to the user. The work described here explores the implications of this in the context of file sharing using occasional reconciliation.