Open Message Queue (OpenMQ or Open MQ) is an open-source message-oriented middleware project by Eclipse Foundation that implements the Java Message Service 3.1 API (JMS). It is the default JMS provider integrated into GlassFish.
In addition to support for the JMS API, OpenMQ provides additional enterprise features including clustering for scalability and high availability, a C API, and a full JMX administration API. It also includes an implementation of the Jakarta Connectors called the JMSRA, that allows OpenMQ to be used by a Jakarta EE compliant application server.
