Messaging Service, part of Sun Microsystem
standard for Enterprise-level computing applications.
JMS uses a publish-subscribe model, whereby an application can register interest in certain message types, and will be in the distribution list for those kinds of messages when the publishing application generates them.
Messaging is an asynchronous form of inter-program communication. This means that the application sending out a message does not expect or wait for a response from the recipients, if any, of the message.