php-event-dispatcher 1.1.0-3 (amd64 binary) in ubuntu quantal

 The Event_Dispatcher acts as a notification dispatch table. It is used to
 notify other objects of interesting things. This information is encapsulated
 in Event_Notification objects. Client objects register themselves with the
 Event_Dispatcher as observers of specific notifications posted by other
 objects. When an event occurs, an object posts an appropriate notification to
 the Event_Dispatcher. The Event_Dispatcher dispatches a message to each
 registered observer, passing the notification as the sole argument.