The Code

Save the following user script as helloworld.user.js:

	Example: Hello World metadata

	// ==UserScript==
	// @name		Hello World
	// @namespace	http://www.oreilly.com/catalog/greasemonkeyhcks/
	// @description	example script to alert "Hello world!" on every page
	// @include		*
	// @exclude		http://oreilly.com/*
	// @exclude		http://www.oreilly.com/*
	// ==/UserScript==

	alert('Hello world!');

There are five separate pieces of metadata here, wrapped in a set of Greasemonkey-specific comments.