Use pybind with new DOM API (at PYNode). - MBScene.document is a PYDocument instead of PYSPDocument. - MBScene.root is a PYNode isntead of PYSPItem. - getNext() was replaced by next(). - attribute() was replaced by getAttribute(). - getID() was removed, use setAttribute() instead. - MBScene.dom was removed, use MBScene.document.root() instead. - MBScene.nodeToItem was removed, use PYNode.spitem instead.

function start_madbuilder() {
    var url = "chrome://MadBuilder/content/madbuilder.html";
    var browser = document.getElementById("content");

    browser.loadURI(url, null, null, true);
}