I've just had my first article ever published on Perl.com. It covers a template module I've written -- in Perl, obviously -- called Template::Recall.

Template systems provide a way to separate concerns, that is, design from logic. I won't cover it here, because that would be more than a tad redundant. If this topic interests you, here's the article link:

http://www.perl.com/pub/a/2008/03/14/reverse-callback-templating.html

Also, you might want to read this conversation on Perlmonks.com:

http://www.perlmonks.org/?node_id=674225

You'll see that template systems are a much debated topic. And if I may venture a personal observation, the Perl language has covered the topic more than any other language out there, and in much greater depth.