1. A computer system for generating application execution trace data, the computer system comprising: first means for launching one or more virtual machines, defining functional characteristics of each of the virtual machines prior to launching each of the virtual machines, and enabling each of the virtual machines to generate event data on occurrence of specified events during application execution on each of the virtual machines; second means for receiving the event data from each of the virtual machines and forwarding the event data; third means for receiving the event data and for generating trace data for storage in a trace file.