A content-based publish/subscribe system is a message-oriented communication facility based on the idea of interestdriven routing. A message, published by the sender without a set destination, is delivered to any and all the receivers that expressed an interest in its content. We refer to this communication style and to the distributed infrastructure that realizes it as content-based communication and contentbased networking, respectively. In this paper we review what we consider the foundations of content-based networking, including some of the major advances of the past years. We then present a vision for further research in this area as well as for the practical realization of a content-based network. In particular, we discuss the implications of content-based communication for the network, the middleware, and applications. Keywords Distributed publish/subscribe systems, content-based communication, content-based networking.
Antonio Carzaniga, Cyrus P. Hall