I use HotDog software (
www.sausage.com). They have a 30 day trial (so that part is free!
). Does great for color coding many web related files (html's, css, php, tpl, asp, etc..). And it won't do stupid stuff to your files and try to do things for you unless you specifically ask it to do something for you. It's great for beginners to advanced. I've used it for 8 years now I think.
This link may also help with smarty.
http://smarty.php.net/docs.php
Good luck!
Carrie