Extending XUL
¥XBL is MozillaÕs Extensible Binding Language
¥Create new elements by using others
¥Develop element node apis

¥<binding id=ÒmytagÓ>
  <content>
    <xul:hbox>
     <xul:button label=ÒButton 1Ó/>
     <xul:button label=ÒButton 2Ó/>
    </xul:hbox>
  </content>
  <implementation>
   <constructor>
    alert(ÒfooÓ);
   </constructor>
  </implementation>
 </binding>