This paper presents DiV ES, a distributed support for the development of networked Distributed Virtual Environments. DiV ES exploits the publish subscribe interaction model to define a flexible communication support. An acyclic peer to peer network of brokers has been defined to support an event based communication framework. The network can be dynamically reconfigured and it can tolerate broker crashes by a proper recovery mechanism. A set of optimization strategies of the basic publish/subscribe routing mechanism has been defined through an accurate analysis of the information exchanged in DV E applications. The message traffic on the network is reduced by packing notifications and filters into a single message. Furthermore, approximated filters are introduced to further reduce message traffic. Advertisement are exploited to optimize the routing of filters.