Publish-subscribe is a message exchange paradigm where one computer program (or just an object on a smaller scale) can subscribe to receive messages and another program (or an object) can publish messages. The publishing entity is called Producer, and the entity receiving messages is a Consumer. Various enterprise software packages provide implementations of the publish-subscribe mechanism, namely Microsoft MessageQueue (MSMQ) or IBM's WebSphere MQ. WebORB includes an implementation of the message routing mechanism with support for remotely located producers and consumers. Additionally, WebORB integrates with other publish-subscribe implementations (i.e. MSMQ, Windows Azure Queue) and can act as an adapter between the supported clients and the actual message distributor.
Publish-subscribe clients supported by WebORB for .NET include Flex, AIR, .NET and Java applications. Future versions of WebORB will include support for AJAX and Silverlight clients.
One of the core concepts in the WebORB publish-subscribe implementation is messaging destination. A message destination represents a pipe where producers can send messages to and consumers can receive messages from. A destination has a logical name and optionally can be configured to integrate with third party message queuing systems.