Vague talk is vague and not examples

You don't need to stuff everything into one file

Here are commands Stucki::Command::Ro Stucki::Command::Sham Stucki::Command::Bo, they correspond to lib/Stucki/Command/Ro.pm

package Stucki::Command::Ro ;
sub run {
   print "Ro ro ro-sham-bo, gently down the stream\n"
}
1;
[download]

They're loaded by by this module

package Stucki;
use Module::Load qw/ load /;
sub run {
    my( $shelf, $command, @rest ) = @_;
    my $plugin = "Stucki::Command::".$command;
    load $plugin; ## or dies
    $plugin->run( @rest );
}
1;
[download]

So from commandline you might use ./stucki ro ast some mo corn where stucki might be

#!/usr/bin/perl --
use Stucki::Frontend::CLI;
Stucki::Frontend::CLI->run;
[download]

And a stucki.cgi might be

#!/usr/bin/perl --
use Stucki::Frontend::CGI;
Stucki::Frontend::CGI->run;
[download]

And so on and so forth...

Some examples of organizing such an "app": Ask, P5U, CPANPLUS/ CPANPLUS::Shell::Default / CPANPLUS::Shell::Tk / CPANPLUS::Shell::Wx
App-Cme-1.002 Check or edit configuration data with Config::Model
Config-Model-2.068 Create tools to validate, migrate and edit configuration files
Config-Model-Approx-1.009 Approx configuration file editor
Config-Model-Backend-Augeas-0.118 Read and write configuration data through Augeas
Config-Model-CursesUI-1.104 Curses interface to edit config data through Config::Model
Config-Model-Itself-1.243 Model editor for Config::Model
Config-Model-LcdProc-2.042 Edit and validate LcdProc configuration file
Config-Model-OpenSsh-1.236 OpenSSH config editor
Config-Model-Tester-2.050 Test framework for Config::Model
Config-Model-TkUI-1.345 Tk GUI to edit config data through Config::Model
Config-Model-Xorg-1.106 Xorg configuration editor and validator

cpan2pkg generating native linux packages from cpan
App::CPAN2Pkg generating native linux packages from cpan
App::CPAN2Pkg::Controller controller for cpan2pkg interface
App::CPAN2Pkg::Lock Simple locking mechanism within cpan2pkg
App::CPAN2Pkg::Module poe session to drive a module packaging
App::CPAN2Pkg::Repository repository details for a given module
App::CPAN2Pkg::Types types used in the distribution
App::CPAN2Pkg::UI::Text text interface for cpan2pkg
App::CPAN2Pkg::UI::Tk main cpan2pkg window
App::CPAN2Pkg::Utils various utilities for cpan2pkg
App::CPAN2Pkg::Worker poe session to drive a module packaging
App::CPAN2Pkg::Worker::Mageia worker dedicated to Mageia distribution
App::CPAN2Pkg::Worker::RPM worker specialized in rpm distributions

math-image display some mathematical images App::MathImage math-image application module App::MathImage::Gtk2::AboutDialog App::MathImage::Wx::Main math-image wxWidgets main window App::MathImage::Tk::Main App::MathImage::Prima::Main

more examples at Re: Recommendations for adding plugin/addon capability to a program and other places