use 5.010;

# Trick perl into thinking that Moose.pm has
# already been required.
$INC{'Moose.pm'} = '/tmp/Moose.pm';

# Require it for real. But perl does nothing!
require Moose;

# Perl thinks Moose is loaded.
say "Moose is loaded" if $INC{'Moose.pm'};

# But it isn't really, so we don't know VERSION.
say 'Moose version:', Moose->VERSION;

##</code><code>##

{
  package My::Plugin;
  ...
}

Something::That::Uses::Plugins->load_plugin('My::Plugin');

##</code><code>##

{
  package My::Plugin;
  ...
  $INC{'My/Plugin.pm'} = __FILE__;
}

Something::That::Uses::Plugins->load_plugin('My::Plugin');