mod_perl may emulate the CGI environment, so that existent Perl CGI scripts may gain from either a performance boost forgoing getting to exist as re-written.

Unlike CGI (& virtually all more web application environments), mod_perl will bring complete access to the Apache API, allowing programmers to easily write handlers for any phase in the Apache asking period, manipulate Apache's internal tables & state mechanisms, part information between Apache processes or threads, alter or even extend a Apache configuration file parser, and add Perl code to the configuration file itself, among more items.