The following licenses apply to the bundled libraries:
OpenTK.dll: http://www.opentk.com/project/license
SdlDotNet.dll/Tao.Sdl.dll: https://www.gnu.org/licenses/lgpl-2.0.html

SDL.dll and SDL_mixer.dll are distributed under the terms of the GNU LGPL license:
http://www.gnu.org/copyleft/lesser.html
SDL source is available from the libraries page at the SDL website:
http://www.libsdl.org/
