MQTTX：跨平台开源的 MQTT 5.0 客户端工具
https://github.com/emqx/MQTTX
https://mqttx.app
MQTTX is a cross-platform MQTT 5.0 client tool open sourced by EMQ, which can run on macOS, Linux and Windows, and supports formatting MQTT payload.
MQTTX simplifies test operation with the help of a familiar, chat-like interface. It’s easy and quick to create multiple, simultaneous online MQTT client connections, and can test the connection, publishing, and subscription functions of MQTT/TCP, MQTT/TLS, MQTT/WebSocket as well as other MQTT protocol features.
