Place this control in a Page Flow and pass it events that will be handled by registered listeners.
Listeners register themselves for this service via the WebLogic management console; classes that implement the EventListener interface may add themselves as listeners using the Configuration tab for the Event Service. Those classes express interest in certain Event types, and when an event of that is dispatched via this service, it is forwarded to the listener.
This control interacts with the EventService EJB, which must be deployed to the application. (The EventService EJB is contained in p13n_ejb.jar, and is deployed with every Portal application.)