>We do what Michael has already said - use BMessages. While it *is* true that >the preferences apps will not be able to read the settings files, everything >else will be compatible. IOW, how they communicate with the system is the >same, even if how they save things isn't. And some *DO* use BMessages. ScreenSaver did. Yes, your R5 screensaver. Look in ~/config/settings/ScreenSaver_settings. The ones that don't? Well, I doubt that any of us want to try to reverse engineer some proprietary format. :-)