Abstract: A system, method, and computer readable medium, for automatically improving performance of, and optimizing, a program based on on-line profile data of the program and profile data (302) collected across multiple runs of the program and stored in a persistent off-line repository (114). The method includes executing a program in an execution environment. Profile data (302) is collected for the program across multiple runs thereof. The performance of the program is improved, such as by optimization of the program, based on on-line profile data of the executing program and the collected profile data in the persistent off-line repository.