title: The difference between a Message Queue, EventBus and a Pub/Sub?
body: <p>I am confused between the concept of Message Queue (e.g., ActiveMQ, RabbitMQ, ZeroMQ) and EventBus (e.g., <a href="https://code.google.com/p/guava-libraries/wiki/EventBusExplained" rel="noreferrer">Guava Event Bus</a>, <a href="http://doc.akka.io/docs/akka/snapshot/java/event-bus.html" rel="noreferrer">Akka EventBus</a>)</p>
  
  <p>I think MQ and eventBus both use the pub/sub pattern. MQ seems more powerful and heavy, compared to Guava.</p>
  
  <p>But what's the real difference? Is EventBus the same as MQ?</p>