mpg321 is Copyright © 2001 Joe Drew, and placed under the GNU General Public License, version 2 or later. It is based on plaympeg, Copyright © 1999 Loki Entertainment Software. The full text of the GNU General Public License can be found in the file /usr/share/common-licenses/GPL-2. mpg321 source includes a copy of fft.c, which is part of the AlsaPlayer, Copyright © 1998 - 2002 . Here is the fft.c license: --------------------------------------------------------------------------- AlsaPlayer 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. AlsaPlayer 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, see . --------------------------------------------------------------------------