http://perl.apache.org/docs/tutorials/tmpl/comparison/comparison.html

specif­i­cal­ly the following:

Introduction

Go on, admit it: you’ve writ­ten a tem­plat­ing sys­tem. It’s okay, near­ly every­one has at some point. You start out with some­thing beau­ti­ful­ly sim­ple like

$HTML =~ s/\$(\w+)/${$1}/g

and end up adding con­di­tion­als and loops and includes until you’ve cre­at­ed your very own unmain­tain­able monster. 

…ummm…

mine actu­al­ly looks like

$codeblock =~ s/<!--\$(.*?)\$-->/${$1}/eg;

just close enough to be depressing.