cython-hidapi can be used under one of three licenses. 1. The GNU General Public License, version 3.0, in LICENSE-gpl3.txt 2. A BSD-Style License, in LICENSE-bsd.txt. 3. The more liberal original cython-hidapi license. LICENSE-orig.txt The license chosen is at the discretion of the user of cython-hidapi. For example: 1. An author of GPL software would likely use HIDAPI under the terms of the GPL. 2. An author of commercial closed-source software would likely use HIDAPI under the terms of the BSD-style license or the original cython-hidapi license.