A general distributed event model

This paper identifies some of the issues that need to be explored in systems that support content-based delivery. Distributed systems today are based on address-based delivery of messages. Each message carries the unique addresses of the intended recipients. The idea in content-based delivery is that information is delivered to those objects that have subscribed for that information. The ideas on content-based delivery reported are based partly on Roman Ginis' doctoral dissertation at Caltech. The ideas on directories reported are based partly on Eve Schooler's doctoral dissertation at Caltech.