Part of meta-issue
- PHPTemplate is based on PHP, and PHP code 1) is complex and 2) can do evil things too easily.
- Evaluate whether Twig might be a better default template engine for Drupal.
- Twig is a template engine that aims to be secure, performant, and to cleanly separate "view logic"/template rendering from functional model/controller code.
- Twig's syntax is not PHP, but rather compound of a macro language. Its syntax reminds a bit of Smarty (and also JSP), but has been architected and developed from scratch, leveraging latest PHP5 features and modern programming standards in the PHP community.
- For starters, create an actual implementation of the template engine in http://drupal.org/project/twig to see how it would look like and whether it's feasible at all.