title: Which hierarchical model for menu and categories is used in CMS like Joomla or WP?
body: <p>Adjaceny or Nested sets model or something else?</p>
  
  <p>I am interested in CMS like Joomla or WordPress and how they deal with menus, categories and other hierarchical datas that are stored in db.</p>
  
  <p>Thanks in advance.</p>