Abstract: In the system of the present invention, the performance of distributed window systems which employ shared libraries is provided. A shared library is a library which is referenced and accessed by multiple processes. Synchronization events are preset in a journal file which, during playback of the same, trigger a mechanism which reads the page table of the current applications. Once the playback is complete, the page table measurements taken during playback are reviewed and information is extracted which is used to determine the working set for shared libraries. Using the working set, the number of pages referenced and the rate of reference can be used to improve performance and predict behavior of other systems.