Smarty
Why don't more PHP based applications use SMARTY?
I've been dabbling with PHP now for a couple years, and have had more then one run in with SMARTY. Actually, all of my sites normally start off using SMARTY until I either get rushed to complete the site and revert to old tactics, or have to settle with another templating system.
Do developers just not like SMARTY? Maybe they just don't know about it?
For those unfamiliar. SMARTY is a templating engine maintained by the guys over at PHP. http://smarty.php.net For those drupal developers out there, you have probably ran into it. While it doesn't ship with drupal, I did find a few templates that came with a modified version. SMARTY pretty much just is a html template, in places you wish to be dynamically replaced you simply enter tags like {$CONTENT}. Then in your php file used to call the template you define what $CONTENT is example: $smarty->assign('content', 'I LOVE SMARTY');
SMARTY is a pain to setup the first time, this is probably a good reason why people tend not to use it. SMARTY reads its templates from a /templates folder, then caches them to templates_c. Developing for it can be a pain, make a change check the page nothing happens.. make another.. nothing happens... OH CRAP I forgot to delete the templates_c cache. It takes a little bit to get used to, but in the end it is much better then templating the old fashion way.
With SMARTY, you could essentially change the entire layout of your site in a very short amount of time.. Compared to some of my earlier projects that started as SMARTY but due to time constraints got bumped to the "Ol` Fasion way".
I haven't quite got SMARTY down to a science yet, but one of these days I will, and then my custom sites will go much much smoother.