This is a mode for editing Smarty PHP templates.
http://www.smarty.net/contribs/syntax_highlighting/emacs/smarty-mode.el
This mode should probably be rewritten to inherit most of it’s functionality from HtmlMode or XmlMode.
A new Smarty-Mode has been written: http://lisp.morinie.fr/smarty/ This mode includes completion, highlight, menus, templates and is customizable. (This is the smarty-mode included in nXhtml that works with MuMaMo.)