Most fit a portion of my requirements, but none that I’ve seen fit all. 
Those requirements are:
[LIST=1]
[]It must be open-source.
[]It must be lightweight… When I say lightweight, I mean I want as little overhead, and as few files, as possible. (Smarty is too bulky for my needs.)
[]Should not force me to cache my files. I’d prefer to have the option to either cache my files or parse the templates at run-time (yes, I’m aware of the performance implications of such a thing, it’s just not always a big deal.)
[]All raw PHP code should be stripped out of the templates prior to parsing. Part of the issue here is that I need to prevent non-developers on my team from destroying our server when deploying dynamic pages.
[*]I should be able to write custom tags. For instance, if I create a new widget for a designer to use in their pages, I’d like to be able to simply associate the widget with a tag, set some filter parameters, and deploy.
[/LIST]
Ideally, it would look and behave similar to Ruby’s Liquid template engine, or the one Django ships with. If need be, I’ll take a few months to write something of my own, but if the wheel already exists somewhere and I’m just not seeing it… well, you know how the saying goes.
Thanks in advance! 'Preciated. 
