Really Small Message Broker

Really Small Message Broker is a small server that uses MQ Telemetry Transport (MQTT) (Version 3) for lightweight, low-overhead messaging. Really Small Message Broker enables messaging to and from tiny devices such as sensors and actuators over networks that might have low bandwidth, high cost, and varying reliability. "Publishers" send messages to the broker, which then distributes the messages to the "subscribers" who have requested to receive those messages.
Really Small Message Broker has a "bridge" that enables connections to other MQTT-capable servers; this bridge allows messages to be passed between Really Small Message Broker instances as well as to other brokers such as Lotus Expeditor micro broker ("Microbroker") and WebSphere Message Broker.
Both Microbroker and Really Small Message Broker can run in embeddded systems in order to provide a messaging infrastructure in remote installations and pervasive environments. However, Really Small Message Broker needs about 100 times less memory to run than Microbroker; therefore, it can extend the reach of the MQTT messaging infrastructure further.
Really Small Message Broker also makes it easy to connect brokers together into a messaging infrastructure (either peer-to-peer or hierarchically). Really Small Message Brokers easy configuration and low resource requirements provide great flexibility in messaging solutions for embedded environments.
Really Small Message Broker will provide you with a lightweight server designed for distributing messages among applications.