MQTT (Message Queue for Telemetry Transport) is a protocol for communicating between two devices (e.g. M2M - Machine to Machine communications).

It is a lightweight protocol that supports pub/sub allowing devices to subscribe to messages published by others, such as watching the temperature published by a thermostat, or a status post from a user.

Read more about the Tinamous MTQQ Broker at the MQTT help page or on the official MQTT org website.

Check out the this talk about MQTT for more details.