The Apache/Perl integration project brings together the full power of the Perl programming language and the Apache HTTP server. With mod_perl it is possible to write Apache modules entirely in Perl. In addition, the persistent interpreter embedded in the server avoids the overhead of starting an external interpreter and the penalty of Perl start-up time.
Mod_perl uses the Apache API to embed a complete Perl interpreter inside Apache. This not only speeds up your CGI programs, but it makes almost all of the Apache API available to the Perl programmer
The Apache server plug-in that embeds a perl in the web server for super-fast performance and increased flexibility.