A communication pattern in which information sources “publish” (i.e., send) information to a somewhat intelligent middleware infrastructure, and information consumers “subscribe” by specifying what kind of information they want to receive from the infrastructure. The middleware must be able to physically transport messages from one or more publishers to one or more subscribers. It also must be smart enough to find the proper destinations by matching each message to subscription criteria. This model naturally supports one-to-many or many-to-many communication — in contrast to either message passing or message queuing, both of which mostly (but not entirely) aim at one-to-one communication.