Often with a framework such as Mojolicious, you totally ditch the CGI paradigm of restarting the script on each request. Many times you will just put the script up in a daemon mode and let it listen, or behind the Hypnotoad preforking webserver, or run it plugged into the Plack middleware.

Mojolicious exposes the request's GET or POST data via the "param" method. It's well documented at Mojolicious::Lite GET/POST parameters. There are also 'req' and 'res' accessors that allow you to get information on the request, and make settings for the response. If you want to explore Mojolicous, start with Mojolicious::Lite, which is a very convenient starting point for lightweight apps. The documentation is pretty easy to get started with.