A DomainSpecificLanguage within PerlLanguage for text output with templating, mainly used for web page generation. Its embedded language provides iteration and greatly simplified access to PerlLanguage data. TemplateToolkit is the popular choice for text formatting inside CatalystFramework and MaypoleFramework.
An example, inside an from the web tutorial:
Links: <ul> [% FOREACH link = webpages %] <li><a href="[% link.url %]">[% link.title %]</a> [% END %] </ul>There's a system for writing plugins to provide various methods inside the templating language.