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.
   http://www.catalystframework.org/

Jifty
   A way to build web applications based on the DRY ("don't repeat yourself") principle.
   http://jifty.org/

Mason HQ
   Mason is a Perl-based web programming language. Among other things, it allows Perl to be embedded in HTML.
   http://www.masonhq.com/

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.
   http://maypole.perl.org/

Perl for the Web
   On-line (and print) book by Chris Radcliff about creating fast dynamic Web sites with Perl.
   http://www.globalspin.com/thebook/

Web Client Programming with Perl
   Full text of the out-of-print book by Clinton Wong.
   http://www.oreilly.com/openbook/webclient/