mod_perl brings together the full power of the Perl programming language
and the Apache HTTP server. You can use Perl to manage Apache, respond to
requests for web pages and much more.

mod_perl gives you a persistent Perl interpreter embedded in your web
server. This lets you avoid the overhead of starting an external interpreter
and avoids the penalty of Perl start-up time, giving you super-fast
dynamic content.

As you'd expect from the Perl community, there are hundreds of modules
written for mod_perl, everything from persistent database connections, to
templating sytems, to complete XML content delivery systems. Web sites like
Slashdot and Wired Magazine use mod_perl. 

WWW: http://perl.apache.org/