Blitz Project http://www.dancres.org/blitz/ The purpose of the Blitz project is to further the use of JavaSpaces and JINI.
ActiveMQ http://activemq.codehaus.org/ ActiveMQ is an open source, Apache 2.0 licensed, high performance Messaging Fabric consisting of a scalable cluster of Message Brokers and a complete JMS 1.1 provider which integrates seamlessly into J2EE containers, light weight containers and any Java application.