This license was found on the "barr" texlive 2010 component. It is Free, but GPL-incompatible.
% This is a package of commutative diagram macros built on top of Xy-pic% % by Michael Barr (email: firstname.lastname@example.org). Its use is unrestricted. It% % may be freely distributed, unchanged, for non-commercial or commercial% % use. If changed, it must be renamed. Inclusion in a commercial% % software package is also permitted, but I would appreciate receiving a% % free copy for my personal examination and use. There are no guarantees% % that this package is good for anything. I have tested it with LaTeX 2e,% % LaTeX 2.09 and Plain TeX. Although I know of no reason it will not work% % with AMSTeX, I have not tested it.%