BSD许可证
The choice of term has little or no impact on which licences are valid or used by the different camps, while recommendations might vary. At least until the release of the GPLv3, the usage of the GPLv2 united the Open source and free software camp. The vast majority of software referred to by all these terms is distributed under a small set of licences, all of which are unambiguously accepted by the various de facto and de jure guardians of each of these terms. The majority of the software is either one of few permissive software licenses (the BSD licenses, the MIT License, and the Apache License) or one of few copyleft licenses (the GNU General Public License v2, GPLv3, the GNU Lesser General Public License, or the Mozilla Public License).