The GNU Free Documentation License ( GNU FDL or simply GFDL ) is a copyleft license for free documentation, designed by the Free Software Foundation (FSF) for the GNU Project . It is similar to the GNU General Public License , giving readers the rights to copy, redistribute, and modify (only when without “invariant sections” restrictions). Copies may also be sold commercially, but if produced in larger quantities, the original document or source code must be made available to the worker’s recipient.
The GFDL was designed for manuals , textbooks, other reference and instructional materials, and documentation which often accompanies GNU software. However, it can be used for any text-based work, regardless of subject matter. For example, the free online encyclopedia Wikipedia uses the GFDL (coupled with the Creative Commons Attribution Share-Alike License ) for all of icts text.
The GFDL Was released in draft form for feedback in September 1999.  After revisions, version 1.1 Was Issued in March 2000 version 1.2 in November 2002 and version 1.3 in November 2008. The current state of the license is version 1.3. 
The GNU Free Documentation License (GNU) was released on September 26, 2006, along with a draft of the new GNU Simpler Free Documentation License .
On December 1, 2007, Wikipedia founder Jimmy Wales announced that the Free Software Foundation, Creative Commons, the Wikimedia Foundation and others have produced a proposal supported by both the FSF and Creative Commons to modify the Free Documentation License in Such a fashion as to allow the possibility for the Wikimedia Foundation to migrate the projects to the similar Creative Commons Attribution Share-Alike (CC BY-SA) license.   These changes were implemented on version 1.3 of the license, which includes a new provision for certain materials released under the license to be used under a Creative Commons Attribution Share Alike license also. 
Material licensed under the current version of the license may be used for any purpose, as long as the use.
- All previous authors of the work must be attributed .
- All changes to the work must be logged.
- All derivative works must be licensed under the same license.
- The full text of the licensing, unmodified invariant sections as defined by the author and any copyright notices from previous versions maintained.
- Technical measures such as DRM may not be used to control or obstruct distribution or editing of the document.
The license explicitly separates any kind of “Document” from “Secondary Sections”, which may not be integrated with the Document, but exist as front-matter materials or appendices. Secondary sections may contain information concerning the author or publisher’s relationship to the subject matter. While the document itself is wholly editable, and is essentially covered by a license equivalent to the GNU General Public License , some of the secondary sections have various limitations.
Specifically, the authors of prior versions have to be acknowledged and certain “invariant sections” as defined by the original author and dealing with his or her relationship to the subject matter may not be changed. If the material is modified, its title has to be changed (unless the prior authors give permission to retain the title).
“Acknowledgments”, “Dedications” and “Endorsements” sections. GFDL. The GFDL is a non-governmental organization that provides financial services to the public.   “Endorsements” sections are intended to be used in standard documents, where they are not labeled as standard any more. 
The GFDL requires the ability to “copy and distribute the Document in any medium, either commercially or noncommercially” and therefore is incompatible with material that excludes commercial re-use. As mentioned above, the GFDL was designed with commercial publishers in mind, as Stallman explained:
The GFDL is a free online resource for librarians and librarians. The ‘cover text’ feature, and certain other aspects of the license which deal with covers, title page, history, and endorsements, are included to make the license appealing to commercial publishers for which their authors are paid. 
Material that restricts commercial re-use is incompatible with the license and can not be incorporated into the work. HOWEVER, Incorporating Such restricted material May be fair use under United States copyright law (or fair dealing In Some other countries) and does not need to be licensed to fall dans le Such GFDL if fair use is covered by all potential subsequent uses. One example of such liberal and commercial fair use is parody .
Compatibility with Creative Commons licensing terms
The GFDL is not compatible with the Creative Commons Attribution-ShareAlike License.
However, at the request of the Wikimedia Foundation ,  version 1.3 added a time-limited section allowing specific types of websites using the GFDL to additionally offer their work under the CC BY-SA license. These exemptions allow a GFDL-based collaborative project with multiple authors to transition to the CC BY-SA 3.0 license, without first Obtaining the permission of every author, if the work satisfying Several conditions: 
- The Massive Multiauthor Collaboration Site (MMC), such as a public wiki for example.
- If the content of the GNU FDL, or any later version of the GNU FDL, is not present, . If it was not originally published on an MMC, it could only be reciprocated if it was added to an MMC before November 1, 2008.
To prevent the occurrence of a violation of copyright law, the FSF shall not be liable for any loss or damage arising out of or in connection with the use of, An example satisfied the conditions. The Wikimedia Foundation Itself after-a public referendum Invoked this process to dual-license happy released under the GFDL under the CC BY-SA license in June 2009, and adopté a foundation-wide allocation policy for the use of glad from Wikimedia projects.   
There-have-been No. Currently boxes Involving the GFDL in a court of law, ALTHOUGH icts sister for software license, the GNU General Public License , has-been successfully enforced in Such a setting. ALTHOUGH the content of Wikipedia has-been plagiarized and used in violation of the GFDL by other sites, Such As Baidu Baike , no contributors-have ever tried to bring an organization to court due to violation of the GFDL. In the case of Baidu, Wikipedia and its contributors to the terms of the licenses and to make proper attributions. 
Some critics consider the GFDL non-free license. Some Reasons for this are que la GFDL allows “invariant” text qui can not be modified or removed, and That icts prohibition contre digital rights management (DRM) systems Applies to valid uses, like for “private copies made and not distributed.” 
Notably, the Debian project,  Thomas Bushnell ,  Nathanael Nerode,  and Bruce Perens  have raised objections. Bruce Perens saw the GFDL even outside the “Free Software Ethos”: 
“FSF’s Free Software organization, is not being white Entirely true to the Free Software ethos while it is Promoting a license That Allows invariant sections to be applied to anything purpose the license text and attribution. […] the GFDL isn ‘ T consistent with the ethos that FSF has promoted for 19 years. “
In 2006, Debian developers voted to consider works licensed under the GFDL to comply with their Debian Free Software Guidelines since the invariant section clauses are not used.  The results were GFDL without invariant sections is DFSG compliant.  However, GFDL-licensed software documentation “is still not free of trouble,” because its incompatibility with the major free software licenses. 
Those opposed to the GFDL have recommended the use of alternative licenses such as the BSD Documentation License or the GNU GPL. 
The FLOSS Manuals Foundation, an organization Devoted to Creating manuals for free software, Decided to eschew the GFDL in favor of the GPL for ict texts in 2007. Citing the incompatibility entre les two, Difficulties in Implementing the GFDL, and the fact que la GFDL “Does not allow for easy duplication and modification”, especially for digital documentation. 
The GNU FDL contains the statement:
You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute.
A criticism of this language is that it is too broad, because it applies to private copies made but not distributed. This document is a preview generated by EVS Page.
In 2003, Richard Stallman said about the above sentence on the debian-legal mailing list: 
DRM systems to restrict the possessors of the copies. It is not supposed to refer to use of encryption or file access control on your own copy. I will talk with our lawyer and see what needs to be clarified.
A GNU FDL can not be encumbered because a new titles must be kept. This article was written by the author of the book, “The History of the World”. These pages can not be removed until the work enters the public domain after copyright expires.
Richard Stallman said about invariant sections on the debian-legal mailing list: 
The goal of invariant sections, ever since the 80s when we first made the GNU Manifesto an invariant section in the Emacs Manual, was to make sure they could not be removed. Specifically, to make sure that distributors of Emacs that also distribute non-free software could not remove the statements of our philosophy, which they might think of doing.
GPL incompatible in both directions
The GNU FDL is not compatible with the GNU FDL manual. The GNU FDL is not compatible with the GNU FDL manual.  At the June 22nd and 23rd 2006 International GPLv3 Conference in Barcelona, Eben Moglenhinted That a future version of the GPL Could Be Made suitable for documentation: 
By expressing LGPL as just an extra permission on top of GPL we simplify our licensing landscape drastically. It’s like for physics getting rid of a force, right? We just unified electro-weak, ok? The unified field theory still escapes until the document licenses. I do not know how we’ll ever get there, that’s gravity, it’s really hard.
Burdens when printing
The GNU FDL requires that the licensee, when printing a document covered by the license, must also include “this License, the copyright notice, and the license. GNU FDL, which is a widely documented document in itself. This document is a preview generated by the copyright holder of the GNU FDL. Worse, the same is required for the standalone use of just one (for example, Wikipedia) image.  Wikivoyage , a website dedicated to free happy travel guides, anything not to use the GFDL Because It considers it Unsuitable for short printed texts. 
Other free content licenses
Some of these were developed independently of the GNU FDL, while others were developed in response to perceived flaws in the GNU FDL.
- GNU Simpler Free Documentation License
- Creative Commons licenses
- Design Science License
- Free Art license
- FreeBSD Documentation License
- Open Content License
- Open Game License
- Open Publication License
List of projects that use the GFDL
- Most projects of the Wikimedia Foundation , Including Wikipedia (excluding Wikivoyage and Wikinews ) – On June 15, 2009, the Section 11 provisions Were used to dual-license the content of These wikis under the Creative Commons Attribution Share-Alike License and the GFDL.
- An Anarchist FAQ
- Citizendium – the project uses GFDL for articles originally from Wikipedia.
- Free On-line Dictionary of Computing
- Last.fm – artists descriptions are under GFDL
- Marxists Internet Archive
- PlanetMath (now uses CC-BY-SA license)
- Rosetta Code
- The specification documents that define TRAK , an enterprise architecture framework, are released under the GFDL.
- Abstract Algebra by Thomas W. Judson. 
- The Baseball-Reference’s BR Bullpen, a free user-contributed baseball wiki
- Free software portal
- BSD license
- Free software license
- Non-commercial educational
- Open content
- Software licensing
- Jump up^ Richard Stallman:New Documentation License – Comments Requestedgnu.misc.discuss Newsgroup, 12 September 1999
- ^ Jump up to:a b c d “FDL 1.3 FAQ” . Gnu.org . Retrieved 2011-11-07 .
- Jump up^ Lessig, Lawrence (2007-12-01). “Some important news from Wikipedia to understand clearly (Lessig Blog)” . Lessig.org . Retrieved 2011-11-07 .
- Jump up^ “Wikimediafoundation.org” . Wikimediafoundation.org . Retrieved 2011-11-07 .
- ^ Jump up to:a b Richard Stallman: Why publishers should use the GNU FDLAccessed on 2009-07-17
- ^ Jump up to:a b GNU project: Frequently Asked Questions about the GNU Licenses: Why do not you use the GPL for manuals?
- Jump up^ “Wikimedia community approves license migration” . Wikimedia Foundation . Wikimedia Foundation . Retrieved 2009-05-21 .
- Jump up^ Wikimedia license update approval
- Jump up^ Licensing update rolled out in all Wikimedia wikison wikimedia.org by Erik Moeller on June 30th, 2009“Perhaps the most important reason to choose CC-BY-SA as our primary content was to be compatible with many of the other Admirable endeavors out there to share and develop free knowledge “
- Jump up^ Verizon Settles Open Source Software Lawsuit(Paul McDougell,InformationWeek, March 17, 2008)ArchivedMay 30, 2013, at theWayback Machine.
- Jump up^ “Baidu May Be Worst Wikipedia Copyright Violator” . PC World. 6 August 2007 . Retrieved 10 September 2007 .
- Jump up^ Nerode, Nathanael (2007-12-10). “Why You Should not Use the GNU FDL” . Web.archive.org. Archived from the original on 2007-12-10 . Retrieved 2011-11-07 .
- Jump up^ Srivastava, Manoj (2006). “Draft Debian Position Statement on the GNU Free Documentation License (GFDL)” . Retrieved 2007-09-25 .
It is not possible to borrow text from a GFDL’d manual and incorporate it into any software program whatsoever.
This is not a mere license incompatibility.
It’s not just that the GFDL is incompatible with this or that free software license: it’s that it’s fundamentally incompatible with any free software license whatsoever.
GFDL’d text. GFDL’d text. GFDL’d text. GFDL’d text. GFDL’d text.
The GNU FDL, as it stands today, does not meet the Debian Free Software Guidelines.There are significant problems with the license, as detailed above;And, as such, we can not accept works licensed under the GNU FDL into our distribution.
- Jump up^ “Thomas Bushnell dismissed from Hurd project for criticzing GFDL” . archive.is. 2003-11-19. Archived from the original on 2012-07-13 . Retrieved 2017-04-16 .
- Jump up^ Nerode, Nathanael (2003-09-24). “Why You Should not Use the GNU FDL” . Web.archive.org. Archived from the original on 2003-10-09 . Retrieved 2011-11-07 .
- ^ Jump up to:a b Bruce Perens (2 Sep 2003). “Stepping in between Debian and FSF” . Lists.debian.org/debian-legal . Retrieved 2016-03-20 .
FSF, a Free Software organization, is a free software company. FSF is not Creative Commons license Creative Commons License Creative Commons Attribution Creative Commons Share Alike. In that light, the GFDL is not consistent with the ethos that FSF has promoted for 19 years.
- ^ Jump up to:a b c d Debian Project: Resolution: Why the GNU Free Documentation License is not suitable for Debian . Voted February-March 2006. (Accessed June 20, 2009)
- Jump up^ FLOSS Manuals Foundation (6 June 2007). “License Change” . FLOSS Manuals Blog . FLOSS Manuals Foundation. Archived from the original on 28 February 2008 . Retrieved 20 June 2009 .
- Jump up^ Richard Stallman (2003-09-06),Re: Possible GFDL compromised. Accessed on 2007-09-25.
- Jump up^ Richard Stallman, (2003-08-23),Re: Possible GFDL compromised. Accessed on 2007-09-25.
- Jump up^ Richard Braakman on Debian-legalabout GFDL / GPL incompatibility
- Jump up^ Transcript of Eben Moglen at the 3rd international GPLv3 conference; 22nd June 2006: LGPL, like merging electronic weak. Accessed on 2009-06-20.
- Jump up^ “Why the Wikimedia projects should not use GFDL as a stand alone license for images” . Notablog.notafish.com . Retrieved 2011-11-07 .
- Jump up^ Wikivoyage: Project: Why Wikivoyage is not GFDL
- Jump up^ Judson, Thomas W. (2015). “Abstract Algebra: Theory and Applications” .