I’d like to report here what I think about templating system in PHP. Some time ago I read a proposal in the Community process forum at Carthag’s site about porting some external template engine in Carthag. The proposal seemed ok to me. Anyway, as said there, we already have the best (IMHO) templating language available: PHP itself.
I think that most of the authors who write a template framework miss this point, and produce some big, slow leviathan like Smarty has become. I include myself to the ones who missed the point, and then realized that PHP itself is a templating system.
Please have a look at carthag.template.Template interface in Carthag platform. And also have a look at the carthag.template.engines subpackage, there is the PhpTemplate class. I think, even without benchmarks, that this is (one of) the fastest and at the same time most powerful template engine available in the PHP world.
iConnect Portal Server uses it, and produces pages very fast, while my old Magellan CMS had a powerful but slow template engine.