Creating a plug-in

I\'m trying to get a better feel for creating plug-ins by creating a simple \"Hello, World!\" plug-in that can be changed (through the admin interface) to issue one of three greetings (\"Hello, World!\", \"Hello, $_USER[username], and a customized text string).

Eventually, this might become a tutorial for other aspiring GL developers, but right now I can\'t find any good documentation that describes HOW GL interacts with plug-ins and how plug-ins work with GL. Is there any documentation (besides the /doc/plugins.html)?

<RANT>
There must be SOME kind of guidelines SOMEWHERE besides...

1. Name your tar-file like this.
2. Put the administrative pages in this directory.
3. Put the user-interace pages in that directory.

...and an obscure list of functions.
</RANT>

Eric P.