HTML::Mason is a full-featured web site development and delivery system. Mason allows web pages and sites to be constructed from shared, reusable building blocks called components. Components contain a mix of Perl and HTML, and can call each other and pass values back and forth like subroutines. Components increase modularity and eliminate repetitive work. HTML::Mason is most powerful when used in conjunction with mod_perl, but can be used in standalone applications as well.
Catalyst is a Web application framework for Perl. It is based on Maypole, and adds many features from Ruby on Rails, Struts, Spring, and Tomcat. The development philosophy focuses on Don't Repeat Yourself, Lego-like components, Code Generation, and very strong testability. It supports a number of plugins, models, views, and controllers.
Config::Maker takes a file with data in simple hierarchical format (similar to BIND and DHCP configuration files) and several templates, and produces the text by filling in the values. It is mainly useful for creating related configuration files. It can be used to generate firewall configuration scripts, DNS zone files, DHCP configuration files, a reference from a single file with all users and machines, etc. It's useful when you are not satisfied with keeping information synchronized in several places, but don't want something as complex as cfengine. Snippets of Perl can be used if all else fails.