MSMQ was originally code named as Falcon. MSMQ enables applications to reliably communicate with each other even in unreliable distributed environments in an efficient yet reliable way where intermediate servers need not be essentially available at all times.
Message Queuing (MSMQ) technology enables applications running at different times to communicate across heterogeneous networks and systems that may be temporarily offline. Applications send messages to queues and read messages from queues. The following illustration shows how a queue can hold the messages used by both sending and receiving applications.
MSMQ also provides Journaling for requests that occur, that can enable greatly in creating in data recovery and system audits.
MSMQ deploys the Store and Forward Mechanism in which messages are not exchanged directly between applications but rather through a message store known as a message queue. This allows applications at each end to be not necessarily available at the same time. MSMQ is not a technology that is brand new, but it is a sincere attempt to standardize and make available the same for Microsoft Platform.