Drop script backgrounder is a freeware app that turns an applescript compiled as a stay open application into a background only app. It does this by editing the "plst" resource. It can also edit this resource in other carbon apps if it exists, but the results of doing that may be unexpected. OSX is less strict about background apps opening windows, they will not crash the machine if they do so like an OS9 app will, but you will not be able to access any menus even if a window is open.

The only way to quit a script that is running as a background process is with another script that just tells it to quit. Otherwise you wont even know it's running unless you look at the process viewer.

This program was originally written as a helper app for acgi dispatcher to let you run acgi programs with apache on OSX the way you could on OS9.

To turn a compiled script application into a background only application just drag and drop it onto the program icon, or into the program window if it's already running. To turn it back to normal drag it into the program again. Backgrounder is smart enough to know if it's already a background app and act accordingly. Dont drag an application that is already running onto backgrounder! If it cannot find the resource of if the resource contains data that backgrounder does not recognize it will not try to edit the program and will return an error while leaving the program untouched.

Though the program has never corrupted a script while I was using it and should not be able to do so, you use it at your own risk and should make a backup copy of your work before converting it.

Drop Script Backgrounder is released as freeware, but a quick email letting me know how your using it would be a nice thought.
This program is made with REALbasic