Editing MIT License (section)

== Ambiguity and variants ==
The name "MIT License" is potentially ambiguous. The Massachusetts Institute of Technology has used many licenses for software since its creation; for example, MIT offers four licensing options for the [[FFTW]]<ref name="MIT-FFTW-licensing">{{cite web|url=https://tlo.mit.edu/technologies/fftw-fastest-fourier-transform-west|title=FFTW - Fastest Fourier Transform in the West|access-date=17 July 2020|publisher=Massachusetts Institute of Technology}}</ref> C source code library, one of which is the [[GNU General Public License|GPL v2.0]] and the other three of which are not [[Open-source software|open-source]]. The term "MIT License" has also been used to refer to the '''Expat License''' (used for the XML parsing library [[Expat (software)|Expat]]) and to the '''X11 License''' (also called "'''MIT/X Consortium License'''"; used for [[X Window System]] by the [[MIT X Consortium]]).<ref name="gnu-license-list-expat" /> Furthermore, the "MIT License" as published by the [[Open Source Initiative]] is the same as the Expat License.<ref name="OSI-MIT">{{cite web|url=http://opensource.org/licenses/MIT|title= The MIT License |publisher=Open Source Initiative|access-date=5 December 2010}}</ref> Due to this differing use of terms, some prefer to avoid the name "MIT License".<ref name="history"/> The [[Free Software Foundation]] argues that the term is misleading and ambiguous, and recommends against its use.<ref name="gnu-license-list-expat" />

The X Consortium was dissolved late in 1996, and its assets transferred to [[The Open Group]],<ref>{{cite web |url=https://invisible-island.net/personal/copyrights.html#bad_dating |title=Copyrights/comments |last=Dickey |first=Thomas E. |access-date=October 6, 2020}}</ref> which released X11R6 initially under the same license. The X11 License<ref name="gnu-license-list-x11" /> and the X11R6 "MIT License" chosen for [[ncurses]] by the Free Software Foundation<ref>{{cite web |url=http://invisible-island.net/ncurses/ncurses.faq.html#is_it_gpl |title=NCURSES&nbsp;— Frequently Asked Questions (FAQ) |last=Dickey |first=Thomas E. }}</ref> both include the following clause, absent in the Expat License:<ref name="gnu-license-list-expat" />

{{Blockquote|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.}}

As of 2020, the successor to the X Window System is the [[X.Org Server]], which is licensed under what is effectively the common MIT license, according to the X.org licensing page:<ref name="xorg-license">{{cite web |url=https://www.x.org/archive/current/doc/xorg-docs/License.html |title=Licenses |website=X.Org Foundation}}</ref>
<blockquote>The X.Org Foundation has chosen the following format of the MIT License as the preferred format for code included in the X Window System distribution.   This is a slight variant of the common MIT license form published by the Open Source Initiative</blockquote>

The "slight variant" is the addition of the phrase "(including the next paragraph)" to the second paragraph of the license text, resulting in: "The above copyright notice and this permission notice (including the next paragraph) shall be included in all copies or substantial portions of the Software." This inclusion clarifies that the liability paragraph must also be included for the conditions of the license to be met.<ref name="xorg-license" />

The license-management features at popular source code repository [[GitHub]], as well as its "Choose a License" service, do not differentiate between MIT/Expat license variants. The text of the Expat variant is presented as simply the "MIT License" (represented by the [[metadata]] tag <code>mit</code>).<ref name="github-license-docs">{{cite web| url=https://docs.github.com/en/free-pro-team@latest/github/creating-cloning-and-archiving-repositories/licensing-a-repository |title=Licensing a repository |website=GitHub Docs}}</ref><ref name="choosealicense-mit">{{cite web |url=https://choosealicense.com/licenses/mit/ |title=MIT License |website=ChooseALicense.com |date=September 5, 2022 |publisher=[[GitHub]]}}</ref>