Mac OS X multi user startup items

For a while, I've been wondering how "Nikon View Monitor Carbon" was starting automatically on my Macs independent of any particular user. This is installed with the software that came with my Nikon film scanner. After some investigating, it appears that besides the usual places (Login Items in System Preferences and the various Startup Items folders), there is a /Library/Preferences/loginwindow.plist file which contains items to startup automatically. There doesn't appear to be any application to view or edit this file outside of the generic Property List Editor or a text editor. It does appear to be in the same format as the ~/Library/Preferences/loginwindow.plist file which is what the Login Items tab in System Preferences saves it's information..