Apache's Synapse

Apache's Synapse - A Web service Mediation Framework project. It is a proposal to build a set of components that work together with Axis2 and other Apache and open source projects to create a flexible transformation, management and routing system. The feature list looks impressive, and the aims of the Synapse as follows:

• a messaging and communications infrastructure;
• based on the principles of service oriented architectures;
• that provides a way of connecting disparate systems;
• that manages the connections and the routing of messages between systems;
• that intermediates and transforms messages and service interactions independently of the endpoint applications;
• that is neutral with respect to the languages and platforms that are integrated - providing first class support for C/C++/COBOL/Java/.NET and other application platforms.
  

This project implements the patterns that are often called Enterprise Service Bus or Broker. You can find more of this on Apache's Incubator.

Source: Apache.