MQTT vs RSMQ: What are the differences?
MQTT: A machine-to-machine Internet of Things connectivity protocol. It was designed as an extremely lightweight publish/subscribe messaging transport. It is useful for connections with remote locations where a small code footprint is required and/or network bandwidth is at a premium; RSMQ: A lightweight message queue for Node.js that requires no dedicated queue server. Just a Redis server. tl;dr: If you run a Redis server and currently use Amazon SQS or a similar message queue you might as well use this fast little replacement. Using a shared Redis server multiple Node.js processes can send / receive messages.
MQTT and RSMQ belong to "Message Queue" category of the tech stack.
RSMQ is an open source tool with 1.07K GitHub stars and 78 GitHub forks. Here's a link to RSMQ's open source repository on GitHub.