MQTT is an important technology for the industrial internet of things (IIoT), building on concepts from IBM’s venerable MQ Series message queue technology. MQTT was initially designed to deliver telemetry from SCADA control systems, with IBM handing the protocol over to the OASIS standards body in 2013.
The standard is deliberately intended to evolve slowly, as it’s embedded in industrial device firmware, and used in hardware that may not get updates—ever. That’s because organizations typically deploy not just tens, or even mere hundreds of MQTT-enabled systems, but many thousands. Plus, MQTT devices are often deployed in inhospitable and hard-to-reach environments, like undersea pipelines, with rollouts often lasting years. MQTT is also relatively simple, with implementations for most common microcontrollers.