This software uses the following libraries in connection with SDL:

libsdl, SDL_image, SDL_mixer and libmikmod are under the GNU Lesser General Public License (LGPL): http://www.gnu.org/copyleft/lesser.html

libpng is under the libpng license: http://www.libpng.org/pub/png/src/libpng-LICENSE.txt

zlib is under the zlib license: http://www.gzip.org/zlib/zlib_license.html