MIT License

The MIT License is a permissive free software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts only very limited restriction on reuse and has, therefore, an excellent license compatibility. The MIT license permits reuse within proprietary software provided that all copies of the licensed software include a copy of the MIT License terms and the copyright notice. The MIT license is also compatible with many copyleft licenses, such as the GNU General Public License (GPL); MIT licensed software can be integrated into GPL software, but not the other way around.Except as contained in this notice, the name(s) of the above copyright holders shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization. The MIT License is a permissive free software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts only very limited restriction on reuse and has, therefore, an excellent license compatibility. The MIT license permits reuse within proprietary software provided that all copies of the licensed software include a copy of the MIT License terms and the copyright notice. The MIT license is also compatible with many copyleft licenses, such as the GNU General Public License (GPL); MIT licensed software can be integrated into GPL software, but not the other way around. As of 2015, it was the most popular software license on GitHub, ahead of any GPL variant and other free and open-source software (FOSS) licenses. Notable projects that use one of the versions of the MIT License include Ruby on Rails, Node.js, jQuery, Nim, and the X Window System. A common form of the MIT License is this (taken from the Open Source Initiative's website; this is identical to the 'Expat License', and different from the license used in the X source code): An intermediate form of license used by the X Consortium for X11 used the following wording: Because MIT has used many licenses for software, the Free Software Foundation considers 'MIT License' ambiguous. 'MIT License' may refer to the Expat License (used for the XML parsing library Expat) or to the X11 License (also called 'MIT/X Consortium License'; used for the X Window System by the MIT X Consortium). The 'MIT License' published by the Open Source Initiative is the same as the 'Expat License'. The X11 License and the 'MIT License' chosen for ncurses by the Free Software Foundation both include the following clause, absent in the Expat License: The original BSD license also includes a clause requiring all advertising of the software to display a notice crediting its authors. This 'advertising clause' (since disavowed by UC Berkeley) is present in the modified MIT License used by XFree86. The University of Illinois/NCSA Open Source License combines text from both the MIT and BSD licenses; the license grant and disclaimer are taken from the MIT License. The ISC license contains similarities to both the MIT and simplified BSD licenses, the biggest difference being that language deemed unnecessary by the Berne Convention is omitted.