RabbitMQ - RabbitMQ is an open source message broker software.
Apache Kafka - Apache Kafka is an open-source message broker project developed by the Apache Software Foundation written in Scala.
CloudMQTT - CloudMQTT implements MQ Telemetry Transport protocol for carrying out messaging using a publish/subscribe message queueing model.
ZeroMQ - ZeroMQ is a high-performance asynchronous messaging library.
EMQX Enterprise - Self-managed scalable and reliable MQTT messaging platform, an all-in-one distributed MQTT broker with multiple protocol gateways and a powerful built-in SQL-based IoT rule engine.
Apache ActiveMQ - Apache ActiveMQ is an open source messaging and integration patterns server.