Carsten Hey authored May 18, 2009 and Chris Hofstaedtler committed Jul 25, 2018

Some free software organisations consider deborphan's former license, the
"Artistic License 1.0", to be non-free.  To prevent future problems in
this regard the copyright holders concordantly agreed to relicense
deborphan and orphaner under the conditions of the MIT License.  Thus,
both are now distributed under the terms of the MIT License, as is the
Debian packaging.

[zeha@d.o: cherry-picked the license change from 1.7.29.x branch;
Andrej Tatarenkow code and name comes back in a follow-up commit]