MO Auto-add terms

This module automatically assigns terms to your pages from their content. This makes it very useful to build a complete site index. It also allows you to offer terms functionality to your users since you can prevent them from adding terms, and yet have terms automatically assigned to their posts. The module can also add parent terms, remove terms that are not in the page anymore, recognize equivalents and synonyms, hide the taxonomy selection box from the edit page. The MO Auto-add terms module comes with the complete source code that you are permitted to modify to better match your website.