The upstream author is: 
Andreas König <andreas.koenig@anima.de>

I've mailed him personally for the package itself (like it's available from
CPAN) lacked any copyright at all.  In his reply he answered:

| Sorry, dass ich die Lizenz vergessen habe. Natuerlich "under the same
| terms as perl", das heisst, wahlweise GPL oder Artistic. Wenn Dir
| wohler ist, wenn ich das noch ergaenze, mache ich auch noch ein neues
| Release.

 Just as I thought this means in english:  It's avaiable under the same terms
as perl itself, upon to your choice under the GPL or Artistic Lincence.

On Debian GNU/Linux systems, the complete text of the GNU General
Public License can be found in `/usr/share/common-licenses/GPL' and
the Artistic Licence in `/usr/share/common-licenses/Artistic'.