From the ePerl
(embedded perl} website at http://www.engelschall.com/sw/eperl/:
ePerl interprets an ASCII file bristled with Perl 5 program statements by evaluating the Perl 5 code while passing through the plain ASCII data. It can operate in various ways: As a stand-alone Unix filter or integrated Perl 5 module for general file generation tasks and as a powerful Webserver scripting language for dynamic HTML page programming.
ePerl includes a module for use with Apache and mod_perl which is supposed to make your dynamically generated pages faster and their source prettier.