JavaSpacesTM technology is a simple unified mechanism for dynamic communication, coordination, and sharing of objects between JavaTM technology-based network resources like clients and servers. In a distributed application,
JavaSpaces technology acts as a virtual space between providers and requesters of network resources or objects. This allows participants in a distributed solution to exchange tasks, requests and information in the form of Java technology-based objects.
JavaSpaces technology provides developers with the ability to create and store objects with persistence, which allows for process integrity.
http://java.sun.com/products/javaspaces/