http://www.underbit.com/products/mad/

MPEG Audio Decoder
  Copyright (C) 2000-2004 Underbit Technologies, Inc.

ID3 Tag Library
  Copyright (C) 2000-2004 Underbit Technologies, Inc.

madplay
  Copyright (C) 2000-2004 Robert Leslie

This program 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 2 of the License, or (at your
option) any later version.

This program 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 this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Some portions of this program may be licensable under different terms.
To inquire about alternate licensing, contact: Robert Leslie <rob@mars.org>
