neal ravindran Middleware is usually something that sits between a client and a server. Or, in simpler terms, between a requestor and a requestee. A request can be considered as a message. Different software components in a distributed computing network need to pass messages between themselves, asynchronously. MOM, or Message Oriented Middleware is software that sits between two such communicating software components. MOM products facilitate this message-passing by using a technique called queueing. Messages are stored in queues until the client which requested it can "read" it in a FIFO fashion, or on a priority basis. The queueing technique thus eliminates complex connection overhead, and also helps the communicating software components work independent of time (or asynchronously). IBM's MQSeries and MS MSMQ are examples of MOMs.