The ebuild says Artistic or GPL, but I cannot find any reference to GPL licensing terms within the tarball.
Not looking deep enough I think. Pod-Parser: If your version of Perl was not distributed under the terms of the Artistic License, than you may distribute PodParser under the same terms as Perl itself. Perl: This program is free software; you can redistribute it and/or modify it under the terms of either: a) the GNU General Public License as published by the Free Software Foundation; either version 1, or (at your option) any later version, or b) the "Artistic License" which comes with this Kit.
Thanks for the explanation.