Gridgain http://www.gridgain.com/ is another great product with Spring and AOP-based grid computing. We have used it successfully after considering Terracotta, Gigaspaces, etc. It's very easy to use and has integration with ESB Mule. More info : http://www.infoq.com/news/2007/05/gridgain We are actually considering implementing a chatty client-server communication in XMPP :)