Message-oriented middleware
Overview
https://en.wikipedia.org/wiki/Category:Message-oriented_middleware
Apache Kafka
Apache Kafka is a distributed event store and stream-processing platform. It is an open-source system developed by the Apache Software Foundation written in Java and Scala.
RabbitMQ
RabbitMQ is an open-source message-broker software (sometimes called message-oriented middleware) that originally implemented the Advanced Message Queuing Protocol (AMQP) and has since been extended with a plug-in architecture to support Streaming Text Oriented Messaging Protocol (STOMP), MQ Telemetry Transport (MQTT), and other protocols. https://en.wikipedia.org/wiki/RabbitMQ
ActiveMQ
Apache ActiveMQ is an open source message broker written in Java together with a full Java Message Service (JMS) client. It provides "Enterprise Features" which in this case means fostering the communication from more than one client or server. Supported clients include Java via JMS 1.1 as well as several other "cross language" clients. The communication is managed with features such as computer clustering and ability to use any database as a JMS persistence provider besides virtual memory, cache, and journal persistency. There's another broker under the ActiveMQ umbrella code-named Artemis. It is based on the HornetQ code-base which was donated[4] from the JBoss community to the Apache ActiveMQ community in 2015. Artemis is the "next generation" broker from ActiveMQ and will ultimately become the next major version of ActiveMQ. https://en.wikipedia.org/wiki/Apache_ActiveMQ