GNU Free Documentation License

The GNU Free Documentation License (GNU FDL or cutty GFDL) is a copyleft license for free content, designed bi the Free Saftware Foondation (FSF) for the GNU project. It is the coonterpairt tae the GNU GPL that gies readers the same richts tae copy, caw aboot an modifee a wark an requires aw copies an affcomes tae be tae haund unner the same license. Copies can be selt commercial an aw, but if duin in lairger quantities (greater nor 100) nor the oreeginal document or soorce code maun be seen on tae the wark's receepient.

The license wis designed for guidals, textbeuks, ither reference an instructional materials, an documentation that aften gangs alang wi GPL saftware. Houaniver, it can be uised for ony text-based wark, regairdless o subject maiter.  The lairgest project uisin the license is Wikipedia, a general-purpose encyclopaedia, but the license isna awfu popular amang ither projects.

 Secondary sections 
The license explicitly separates ony kynd of "Document" frae "Secondary Sections", which mey nae be integrated wi the Document, but exist as front-matter materials or appendices. Seicontar sections can contain information regarding the author's or publisher's relationship tae the subject matter, but nae ony subject matter itself. While the Document itself is wholly editable, an is essentially covered bi a license equivalent tae (but baith-ways incompatible wi) the GNU General Public License, some o the seicontar sections hae various restrictions designed primarily tae deal wi proper attribution tae previous authors.

Specifically, the authors of prior versions hae tae be acknowledged an certaint "invariant sections" specified bi the oreeginal author an dealing wi his or her relationship tae the subject matter mey nae be changed. If the material is modified, its title haes tae be changed (unless the prior authors gie permission tae retain the title). The license an aa haes provisions for the handling of front-kiver an back-kiver texts of beuks, as well as for "History", "Acknowledgements", "Dedications" an "Endorsements" sections.

 Commercial redistribution 
The GFDL requires the ability tae "copy and distribute the Document in any medium, either commercially or noncommercially" an therefore is incompatible wi material that excludes commercial re-use. Material that restricts commercial re-use is incompatible wi the license an canna be incorporated intae the work. Houiver, incorporating sic restricted material mey be fair use unner United States copyright law an daes nae need tae be licensed tae faw within the GFDL if sic fair use is covered bi aw potential subsequent uses. Ane good ensaumple of sic liberal an commercial fair use is parody.

 Criticism of the GFDL 
The Debian project an Nathanael Nerode haes raised objection. Debian developers eventually voted tae consider works licensed unner the GFDL tae comply wi thair Debian Free Software Guidelines providit the invariant section clauses are nae uised. Thir critics recommend the use of alternate licenses sic as the share-alike Creative Commons licenses or even the GNU GPL. Thay consider the GFDL a non-free license. The reasons for this are that the GFDL allows "invariant" text which canna be modified or removed, an that its prohibition against digital rights management (DRM) seestems applies tae valid usages, lik for "private copies made and not distributed". 

 Overly broad DRM clause 
The GNU FDL conteens 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 leid is that it is too broad, acause it applies tae private copies made but nae distributed. This means that a licensee is nae allowed tae save document copies "made" in a proprietary file format or uisin encryption.

In 2003, Richard Stallman said aboot the abuin sentence on the debian-legal mailing leet:

"This means that you cannot publish them under DRM systems to restrict the possessors of the copies. It isn't supposed to refer to use of encryption or file access control on your own copy. I will talk with our lawyer and see if that sentence needs to be clarified."

As of 2006, the sentence haes nae yet been clarified.

 Invariant sections 
A GNU FDL wark can quickly be encumbered acause a new, different, title maun be giv'n an a leet o previous titles maun be kept. This coud lead tae the situation whaur thar are a whol series o title peiges, an dedications, in ilka an e'ery copy o the beuk if it haes a lang lineage. Thir peiges cannae e'er be remuived, at least nae until the wark haes enter'd the public domein efter copyricht expires.

Richard Stallman said aboot invariant sections on the debian-legal mailin leet:

"The dool o invariant sections, e'er syne the 80s whan we first made the GNU Manifesto an invariant section in the Emacs Manual, wis tae mak sure they coud nae be remuived. Specifically, tae mak sure that distributors o Emacs that awso distribute non-free software coud nae remuive the steitments o wir philosophy, whilka they micht think o doin acause those steitements criticize their actions."

 GPL incompatible in both directions 
The GNU FDL is incompatible in baith directions wi the GPL: that is GNU FDL material canna be put intae GPL code an GPL code canna be put intae a GNU FDL manual. Because of this, code samples are eften dual-licensed sae that thay mey appear in documentation an can be incorporated intae a free software program.

At the Juin 22nt an 23rd internaitional GPLv3 conference in Barcelona, Moglen hinted that a future version o the GPL coud be made suitable for documentation:
By expressing LGPL as just an additional 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 grand unified field theory still escapes us until the document licences too are just additional permissions on top of GPL. I don't know how we'll ever get there, that's gravity, it's really hard.

 Burdens when printing 
The GNU FDL requires that licensees, when prentin a document covered bi the license, must an aa include "this License, the copyright notices, and the license notice saying this License applies to the Document". This means that if a licensee prints oot a copy of an article whose text is covered unner the GNU FDL, he or she must an aa include a copyright notice an a physical printout o the GNU FDL, which is a significantly lairge document in itself.

 Ideological tone 
The license haes a preamble, which some critics dislike acause of its ideological tone. Because the preamble is pairt o the license, it must be included (alang wi the rest o the license's text) wi every copy o a licensed document.

 Transparent formats 
The definition o a "transparent" format is complicated, an mey be difficult tae apply. For ensaumple, drawings are required tae be in a format that allows them tae be revised straightforwardly wi "some widely available drawing editor." The definition of "widely available" mey be difficult tae interpret, an mey chynge ower time, syne, e.g., the open-soorce Inkscape editor is rapidly maturing, but haes nae yet reached version 1.0. This section, which wis rewritten somewhat atween versions 1.1 an 1.2 o the license, uses the terms "widely available" an "proprietary" inconsistently an wioot defining them. Accordin tae a strict interpretation o the license, the references tae "generic text editors" coud be interpreted as ruling oot a format uised bi an open-soorce wird-processor sic as Abiword; accordin tae a loose interpretation, houiver, Microsoft Word .doc format coud qualify as transparent, syne a subset of .doc files can be edited perfectly uisin OpenOffice.org, an the format therefore is nae ane "that can be read and edited only by proprietary word processors."

 History 
The FDL wis released in draft form for feedback in late 1999. Efter revisions, version 1.1 wis issued in Mairch 2000, an version 1.2 in November 2002. The current state o the license is version 1.2.

The first discussion draft o the GNU Free Documentation License version 2 wis released on September 26 2006, alang wi a draft o the new GNU Simpler Free Documentation License.

The new draft o the GNU FDL includes a nummer of improvements, sic as new terms crafted during the GPLv3 process tae improve internationalization, clarifications tae help fowk applying the license tae audio an video, an relaxed requirements for uisin an excerpt frae a work.

The new proposed GNU Simpler Free Documentation License haes no requirements tae maintain Cover Texts an Invariant Sections. This will provide a simpler licensing option for authors who dae nae wish tae use thir features in the GNU FDL.

 Other free content licenses 
Some of thir war developed independently o the GNU FDL, while others war developed in response tae perceived flaws in the GNU FDL.
 Creative Commons licenses
 Design Science License
 Free Art license
 Open Content License
 Open Publication License

 See also 
 BSD license
 Copyright
 Copyleft
 Free software license
 GNU
 Open content
 Share-alike
 Software licensing 
 Non-commercial educational

 External links 
 GFDL official text
 The GNU Free Documentation License
 Free Software and Free Manuals
 Draft of Debian position statement about the GFDL
 Why You Shouldn't Use the GNU FDL 
 Why Wikivoyage isna GFDL: Problems wi uisin the GFDL for short printed texts
 The Free Universal Encyclopedia And Learning Resource
 Guide to the new drafts of documentation licenses 

Category:GNU Project
Category:Free content licenses
Category:Saftware documentation
Category:Copyleft
Category:Free Software Foundation