ZMQ has good documentation and there is a wide array of wrappers for different languages. It is ideal for high performance responsive messaging across different platforms and technologies. I personally used it to send low latency messages between an embodied Linux (c++) machine and a windows computer (c#). It also has a wide array of implementations so legacy systems can communicate with newer systems.

What I liked about ZeroMQ the most is that it is very easy to use. We had at the same project two queue implementations: ZeroMQ and Kafka. Kafka was for heavy loaded installations and ZeroMQ for the rest. And ZeroMQ had only one configuration class that created a ZSocket bean, that's it. Now you just use "zmqPublisher.send" to push your message into the queue. For comparison Kafka had 15 classes and interfaces for configuration a publisher. The same with the subscriber.

Lightweight and best for high throughput and low latency systems