ref: 81b9d111738d1bb5e8038b7f5c0f93a6242a8e71
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 libst are licensed under the less restrictive LGPL. Note that some of the external packages that can be linked in to libst are GPLed and/or may have licensing problems, so they can be disabled at configure time with the relevant--with-* options. If libst is built with such libraries, it must be distributed under the GPL.