Open
Description
This client support both MQTT v3.1.1 and v5 protocol and it is Java 8 and Reactive ready: https://github.com/hivemq/hivemq-mqtt-client
Unlike Paho which is not clear when will support v5: https://github.com/eclipse/paho.mqtt.java/blob/master/MQTTv5.md
Although I might agree that this could be something for version 6.0 or we can support both clients since 5.3...