alright, at your first post I though you were reloading program code while a progam is running. Instead your changing launch properties of the program via the program being launched while its running. the best way to do this via the program is to edit the file using the cocoa framework instead of a script (documentation here<http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Conceptual/PropertyLists/ReadWritePlistData/ReadWritePlistData.html#//apple_ref/doc/uid/10000048i-CH8-SW1>) and using the system() call from stdlib "system("launchd load com.yourdomain.yourprogram); " I still have no idea why you think the program should be changed by the server instead of a client but whatever. such a repetitive, brainless task should be left as stateless as possible to allow easy debugging. when you change things programmaticly, if that change isn't absolutely predictable, things get unstable quickly.