EMQ is a scalable open source multiplatform MQTT broker. It’s written in Erlang/OTP for higher performance, handling millions of concurrent connections. It supports multiple protocols including MQTT, MQTT Sensor Networks, CoAP as well as WebSockets, making it suitable for both IoT and mobile devices. We’ve started using EMQ in our projects and have enjoyed its ease of installation and use, its ability to route messages to different destinations including Kafka and PostgreSQL, as well as its API-driven approach for its monitoring and configuration.