Microsoft Message Queuing (MSMQ) is a messaging protocol that allows applications running on separate servers to communicate in a failsafe manner. It enables applications to send messages to each other via queues, ensuring that messages are not lost even if the sending or receiving application is temporarily offline. MSMQ supports both local and remote communication and provides features such as message persistence, security, and transactional support. It is commonly used in enterprise environments for reliable and asynchronous communication between different components of an application or across disparate systems.

Microsoft Message Queuing (MSMQ) is a message queue implementation developed by Microsoft and deployed in its Windows Server operating systems. It's a technology for asynchronous communication that allows applications running on separate servers or processes to communicate in a failsafe manner.

This is achieved by placing messages in queues, where they can be retrieved reliably when conditions permit. This functionality allows for effective communication across networks and between computers that may not always be directly connected.

The reliable delivery of messages makes MSMQ a widely used tool in enterprise software. It ensures this delivery by storing messages that fail to reach their designated destination in a queue, from where they are re-sent once the destination is reachable again. MSMQ also provides support for security and priority-based messaging.

MSMQ supports both durable and non-durable messaging, allowing for a trade-off between performance and consistency, and it also supports transactions. This means multiple operations across multiple queues can either all be executed, or none at all, thus maintaining the consistency of operations.

Introduced in 1997, MSMQ has been a part of Microsoft platforms and is incorporated into Microsoft Windows components like the Windows Communication Foundation (WCF), offering secure, reliable transport with a unified programming model compatible with other communication standards.

MSMQ has undergone various updates and versions since its initial release, with each version introducing new features and improvements. It's used in various Windows platform-based applications requiring internal notifications and services.