ripple-core/LICENSE.txt

Ripple is an interactive audience response system that allows presenters to survey audience members in real time communication through their mobile devices.

Ripple, Copyright (C) 2012, 2013 University of Oregon, Interactive Media Group

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

Ripple 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with Ripple.  If not, see <http://www.gnu.org/licenses/>.