Licences
The choice of term has little or no impact on which licences are valid. The vast majority of software referred to by 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. 50-70% of this software is under the GNU General Public License, and most of the rest is distributed under the terms of the GNU Lesser General Public License, the BSD licenses, the Mozilla Public License, the MIT License, and the Apache License, each with a share of between 2% and 10%.
The Free Software Foundation and the Open Source Initiative each publish lists of licences that they accept as complying with their definitions of free software and open source software respectively.
- List of FSF approved software licences
- List of OSI approved software licences
Apart from these two organisations, the Debian project is seen by some to provide useful advice on whether particular licences comply with their Debian Free Software Guidelines. Debian does not publish a list of "approved" licences, but its judgments can be tracked by checking what licences are used by software they have allowed into their distribution. In addition, the Fedora Project does provide a list of approved licences (for Fedora) based on approval of the Free Software Foundation (FSF), the Open Source Initiative (OSI), and consultation with Red Hat Legal.
Read more about this topic: Alternative Terms For Free Software