#!/usr/bin/perl

use ExtUtils::Installed;

my $instmod = ExtUtils::Installed->new();

foreach my $module ($instmod->modules()) {
    my $version = $instmod->version($module) || "???";
    print "$module -- $version\n";
}

This is a handy little bit that will show you all of the installed modules on the system.

Find Installed Modules

perl

Perl