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.
The persistent interpreter embedded in the server avoids the overhead
of starting an external interpreter and the penalty of Perl start-up
time.

Note that you do not need mod_perl to run perl scripts via the common
gateway interface (CGI). mod_perl enables you to run Perl scripts in an
embedded interpreter if the additional performance is needed, but may
require modifications to the scripts.

Usage:

To load the module into Apache, run the command "a2enmod perl" as root.

To learn about the configuration, the best reference unequivocally is
http://perl.apache.org/docs/

For porting 1.0 applications to 2.0, the page
http://perl.apache.org/docs/2.0/user/porting/compat.html should give
the required information.

Most mod_perl handlers use the perl-script handler. Scripts can run in
"mod_perl mode" (preconfigured for URLs starting with /perl/) or "perl
cgi mode" (preconfigured for URLs starting /cgi-perl). Plain CGI
scripts can be run via /cgi-bin/. In all these cases, the script would
be placed inside the /srv/www/cgi-bin/ directory. Refer to
/etc/apache2/conf.d/mod_perl.conf about this configuration.