There are a lot of search engines in Perl.Most of the sites uses CGI script for displaying the pages.Some of the free and proprietary sites are as follows.
Dansie Search Engine
Extropia Site Search (free)
F3DSearch
FluffySearch (free but no support)
Fluid Dynamics Search
Global Data SiteSearch (free)
Htgrep
HTTP::Index module (free)
KSearch
Matt's Simple Search (free)
Perlfect Search (free)
RuterSearch (free)
RiSearch (some versions free, some paid)
Selena Sol's Keyword Search (now Extropia Site Search, free)
Sphinx new javaOpen Source Code Unix-based tool windows-based tool Mac OS X
WebSearch Perl Script