The basic idea is to package it up and have your users install it just like all other modules: perl Makefile.PL; make; make test; make install. If you use, for example, Module::Install's auto_install, this will cause all the prereqs to be installed, too.

If you want even simpler, you could write a wrapper script which downloads the tarball, runs the untar commands, and then runs perl Makefile.PL, etc., for the user. That's not too hard on unix/linux - but may be a bit more work on Windows, since Windows doesn't come with handy things like wget or tar or gzip, and requiring things like LWP kind of defeats the idea. But your script could install LWP and Archive::Tar and such before downloading your tarball by using ppm, I think, though I've never tried.

#!/usr/bin/perl

use strict;
use warnings;
use CPAN;

CPAN::Shell->install('CGI');
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How do you find the dependencies? An easy way is to use CPAN::FindDependencies. Download it, then run this script to get a record:

#!/usr/bin/perl

use strict;
use warnings;
use CPAN;

open STDOUT, '>', '/root/Desktop/CGIdeps';
system("cpandeps CGI");
close STDOUT;
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Next, to determine which modules are core, you want to use Module::CoreList. From the command line, do corelist CGI. It'll tell you that it's core.

Is CGI core only or dual-lived? Use App::DualLivedList. From the command line, do dual-lived CGI. It'll tell you if it's dual-lived.

The finished script should look something like this:

#!/usr/bin/perl

use strict;
use warnings;
use CPAN;

CPAN::Shell->install(
"FCGI",
"Scalar::Util",
"File::Spec",
"Test::Harness",
"Test::More",
"CGI");
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What's in core varies from one version of perl to another, so unless you also nail down *exactly* what version of perl your application is for, then you may need to be a bit clever about core modules. But only a bit clever, cos it's pretty easy really.

For every module that you depend on, including core modules, check to see if a recent enough version of it is installed. If not, add it to the list of modules that you need to install. Many core modules (at least of those which haven't been in core since forever) are dual-lived so also exist independently on the CPAN.

Your script will end up looking something like this ...

#!/usr/bin/perl

use strict;
use warnings;
use CPAN;

my %needed = (
  Some::Module => 1.23, # must have at least version 1.23
  Other::Module => 0, # any old version will do
  ...
);
my @need_to_install = ();
foreach my $module (keys %needed) {
  eval "use $module;";
  if($@ || eval "${module}::VERSION < $needed{$module}") {
    push @need_to_install, $module;
    next;
  }
}
CPAN::Shell->install(@need_to_install);
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Pehraps you want to package your application and dependencies using PAR or pp. See http://par.perl.org for further details.