ref: 3f52aa4e496f491a14a596eb0055f0ed92a2d30f
dir: /COPYING/
SoX source code is distributed under two main licenses. The two licenses are in the files LICENSE.GPL and LICENSE.LGPL. sox.c, and thus SoX-the user application, is distributed under the GPL, while the files that make up libsox are licensed under the less restrictive LGPL. Note that some of the external packages that can be linked into libsox are GPLed and/or may have licensing problems, so they can be disabled at configure time with the relevant--with-* options. If libsox is built with such libraries, it must be distributed under the GPL.