This is rabbitmq-server, a message broker implementing AMQP, STOMP and MQTT.

Most of the documentation for RabbitMQ is provided on the RabbitMQ web
site. You can see documentation for the current version at:

http://www.rabbitmq.com/documentation.html

and for previous versions at:

http://www.rabbitmq.com/previous.html

Man pages are installed with this package. Of particular interest are
rabbitmqctl(1), to interact with a running RabbitMQ server, and
rabbitmq-plugins(1), to enable and disable plugins. These should be
run as the superuser.

An example configuration file is provided in the same directory as
this README. Copy it to /etc/rabbitmq/rabbitmq.config to use it. The
RabbitMQ server must be restarted after changing the configuration
file or enabling or disabling plugins.