Mozilla::DOM::Supports is a wrapper around an instance of Mozilla's nsISupports interface, from which everything else inherits.
This is how you can get different interfaces from an object. Basically that means a way to get different methods from the same object.
The $obj return value will be blessed into the class corresponding to whatever interface you requested.
The $uuid argument is just a string which looks something like
which you can find in the Mozilla header files, but it's better to use a GetIID class method, like
$uuid = Mozilla::DOM::EventTarget->GetIID();
Copyright (C) 2005-2007, Scott Lanning
This software is licensed under the LGPL. See Mozilla::DOM for a full notice.