A computer implemented method for event notification for a computer, the method comprising: receiving, at a notification manager of said computer, a plurality of event registration requests, each registration request comprising: a request for registering a requestor program to receive notification of one or more events detectable by a notifier program; a first identifier identifying the requestor program; and a second identifier identifying the notifier program each notifier program responsive to occurrence of events of a corresponding event class by detecting an event from the event class and providing notification of an occurrence of the event; responsive to each registration request, storing, by the notification manager, the first and second identifiers in a map; activating a number of event notifier programs; responsive to receiving notification from a particular one of said notifier programs after detection of an occurred event, performing by the notification manager, steps comprising: accessing the map to identify all requestor programs having submitted registration requests concerning the particular one of the notifier programs; and activating the identified requestor programs and transmitting to each a representation of the occurred event. receiving, at a notification manager of said computer, a plurality of event registration requests, each registration request comprising: a request for registering a requestor program to receive notification of one or more events detectable by a notifier program; a first identifier identifying the requestor program; and a second identifier identifying the notifier program each notifier program responsive to occurrence of events of a corresponding event class by detecting an event from the event class and providing notification of an occurrence of the event; responsive to each registration request, storing, by the notification manager, the first and second identifiers in a map; activating a number of event notifier programs; responsive to receiving notification from a particular one of said notifier programs after detection of an occurred event, performing by the notification manager, steps comprising: accessing the map to identify all requestor programs having submitted registration requests concerning the particular one of the notifier programs; and activating the identified requestor programs and transmitting to each a representation of the occurred event. a request for registering a requestor program to receive notification of one or more events detectable by a notifier program; a first identifier identifying the requestor program; and a second identifier identifying the notifier program each notifier program responsive to occurrence of events of a corresponding event class by detecting an event from the event class and providing notification of an occurrence of the event; responsive to each registration request, storing, by the notification manager, the first and second identifiers in a map; activating a number of event notifier programs; responsive to receiving notification from a particular one of said notifier programs after detection of an occurred event, performing by the notification manager, steps comprising: accessing the map to identify all requestor programs having submitted registration requests concerning the particular one of the notifier programs; and activating the identified requestor programs and transmitting to each a representation of the occurred event. accessing the map to identify all requestor programs having submitted registration requests concerning the particular one of the notifier programs; and activating the identified requestor programs and transmitting to each a representation of the occurred event.