I know there are files to upload on the server and another file to run for the install. I'd like to know what goes on in the background. Does the addon create templates? I don't see any new ones. How does the addon perform it's task?
The XML file has all templates, phrases, navigation entries, install / uninstall routines, etc for the addon. All of those things are done when you import the XML (after you have uploaded the files for the addon).