WiringPi/debian/copyright

wiringPi is Copyright (C) 2012-2015 Gordon Henderson.

wiringPi is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License, as published
by the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

wiringPi is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

On all Debian and Raspbian systems, a copy of the GNU Lesser General
Public License version 3 can be found in
`/usr/share/common-licenses/LGPL-3'.