Catalyst - - "The elegant MVC framework". Designed with flexibility in mind, it lets the user choose among a variety of storage models, templating systems, web servers, and operating systems.
Jifty - - A way to build web applications based on the DRY ("don't repeat yourself") principle.
Mason HQ - - Mason is a Perl-based web programming language. Among other things, it allows Perl to be embedded in HTML.
Maypole - - Perl framework for MVC-oriented web applications, designed to minimize coding requirements for creating simple web interfaces to databases, while remaining flexible enough to support enterprise web applications.
Perl for the Web - - On-line (and print) book by Chris Radcliff about creating fast dynamic Web sites with Perl.