This demo shows you how mootools-history never actually reloads the page. In more recent browsers, it changes the URL and in older browsers it uses the hash. You can find the source of the demo here.
Click some links and check the native back/forward button in your browser.
Clicking any link will load all the content into the page via XHR. All new links will receive the listener via the "update"-method in the demo. For more advanced handling of generically changing content, see mootools-dynamic-matcher