Microsoft Message Queue Server (MSMQ) is part of the Microsoft NT Server set of products. It was first made widely available in the Windows NT 4 Option Pack. MSMQ is also included as part of Windows NT Server Enterprise Edition in a complete implementation. A more limited implementation is available on the regular Windows NT Server. There are clients available for every Windows platform, as well as for other platforms, such as IBM CICS and MQSeries. MSMQ provides the technologies that allow the transmission of messages over network connections, management of these messages as they are grouped into queues, and a programmatic API that allows developers to access all of the functionality of this technology.
MSMQ also provides ActiveX support for working with messages and queues. It is this ActiveX support that provides the close integration between MSMQ and IIS, ASP, and MTS. MSMQ can be enabled to understand the relative costs of connections, and thereby choose the most efficient routing method for messages within a network infrastructure. As with many of the other tools that are part of the BackOffice family, MSMQ provides graphical management through the Microsoft Management Console (MMC) which provides centralized management facilities for even the most widely distributed systems.