Very nice, but doesn't work for 5.8.8 in Slackware 12.0:

$ perldoc Module::CoreList
No documentation found for "Module::CoreList".
$ perl -V
Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
  Platform:
    osname=linux, osvers=2.6.18.6, archname=i486-linux-thread-multi
[snip]
[download]

With Perl 5.8.5:

C:\>corelist Module::CoreList

Module::CoreList  was not in CORE (or so I think)
[download]

But the nice thing is, you can install it on any version of Perl via cpan.

With Perl 5.10 (Strawberry):

C:\>corelist Module::CoreList

Module::CoreList was first released with perl 5.009002
[download]

So, starting at 5.10, you don't need to install it necessarily.