Lingua::EN::Words2Nums is a Debian native package. 

Copyright 2001-2003 Joey Hess <joey@kitenet.net>

This module is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

That means it's dual licensed under the GPL
(/usr/share/common-licenses/GPL) and Artistic
(/usr/share/common-licenses/Artistic) licenses.