A first computer system is monitored for alterations of a program landscape which includes multiple applications configured to operate on the first computer system. An alteration of the program landscape is detected and aspects of the alteration of the program landscape are determined. A catalog of additional computer systems which are associated with the first computer system is accessed. That a second computer system of the accessed catalog of additional computer systems should receive an event notification is determined. An event notification including information corresponding to the determined aspects of the alteration of the program landscape is generated. The event notification including the event information is sent from the first computer system to the second computer system.