In a distributed system including a debug server and debug clients coupled for data communications through a network, where the debug server includes a debug administrator, message router, back-end debugger, and a debuggee, collaborative software debugging includes: presenting a client-specific GUI; detecting user input through the GUI, including user input specifying a location to establish an event; establishing a client-specific event alert to be invoked upon receipt of an event notification for the event; generating application-level messages, including a request to establish the event; sending application-level messages to the debug server, including the request; receiving client-specific debug results, including an event notification for the event; and displaying the client-specific debug results, including invoking the client-specific event alert responsive to the event notification, without invoking an alert by at least one of the other debug clients receiving the event notification.