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 a work and requires all copies and derivatives to be
available under the same license. Copies may also be sold
commercially, but, if produced in larger quantities (greater than
100), the original document or source code must be made available
to the work's recipient.
The GFDL was designed for
manual,
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 used to use the GFDL for all of its
text.
Timeline
The FDL 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 first discussion draft of the GNU Free Documentation License
version 2 was released on
September 26
2006, along with a draft of the new
GNU Simpler Free
Documentation License.
On
December 1 2007,
Jimmy Wales announced that a long period
of discussion and negotiation between and amongst the Free Software
Foundation, Creative Commons, the Wikimedia Foundation
and others had 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 allowing certain materials released under
the license to be used under a Creative Commons Attribution
Share-Alike license also.
Conditions
Material licensed under the current version of the license can be
used for any purpose, as long as the use meets certain
conditions.
- 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 license, unmodified invariant sections as
defined by the author if any, and any other added warranty
disclaimers (such as a general disclaimer alerting readers that the
document may not be accurate for example) and copyright notices
from previous versions must be maintained.
- Technical measures such as DRM may not be used to control or
obstruct distribution or editing of the document.
Secondary sections
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 can contain information regarding the author's
or publisher's relationship to the subject matter, but not any
subject matter itself. While the Document itself is wholly
editable, and is essentially covered by a license equivalent to
(but mutually incompatible with) the
GNU General Public License, some
of the secondary sections have various restrictions designed
primarily to deal with proper attribution to previous
authors.
Specifically, the authors of prior versions have to be acknowledged
and certain "invariant sections" specified 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).
The license also has provisions for the handling of front-cover and
back-cover texts of books, as well as for "History",
"Acknowledgements", "Dedications" and "Endorsements" sections.
These features were added in part to make the license more
financially attractive to commercial publishers of software
documentation, some of whom were consulted during the drafting of
the GFDL. "Endorsements" sections are intended to be used in
official standard documents, where distribution of modified
versions should only be permitted if they are not labeled as that
standard any more.
Commercial redistribution
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: Material that restricts
commercial re-use is incompatible with the license and cannot 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
within the GFDL if such 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
Although the two licenses work on similar copyleft principles, the
GFDL is not compatible with the
Creative Commons Attribution-ShareAlike license.
However, version 1.3 added a new 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 (which
would normally require the permission of every author), if the work
satisfies several conditions:
- The work must have been produced on a "Massive Multiauthor
Collaboration Site" (MMC), such as a public wiki for example.
- If external content originally published on a MMC is present on
the site, the work must have been licensed under Version 1.3 of the
GNU FDL, or an earlier version but with the "or any later version"
declaration, with no cover texts or invariant sections. If it was
not originally published on an MMC, it can only be relicensed if it
were added to an MMC before November 1, 2008.
To prevent the clause from being used as a general compatibility
measure, the license itself only allowed the change to occur before
August 1st, 2009. At the release of version 1.3, the FSF stated
that all content added before November 1, 2008 to Wikipedia as an
example satisfied the conditions. The Wikimedia Foundation itself
after a public referendum, invoked this process to dual-license
content released under the GFDL under the CC-BY-SA license in June
2009, and adopted a foundation-wide attribution policy for the use
of content from Wikimedia Foundation projects.
Enforcement
There have currently been no cases involving the GFDL in a court of
law, although its sister license for software, 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 representatives asked the site and its
contributors to respect the terms of the licenses and to make
proper attributions.
Criticism
Critics consider the GFDL a non-free license. Some reasons for this
are that the GFDL allows "invariant" text which cannot be modified
or removed, and that its prohibition against
digital rights management (DRM)
systems applies to valid usages, like for "private copies made and
not distributed".
Notably, the
Debian project and
Nathanael Nerode have raised objections. In
2006, Debian developers voted to consider works licensed under the
GFDL to comply with their
Debian Free Software
Guidelines provided the invariant section clauses are not used.
However, their resolution stated that even without invariant
sections, GFDL-licensed software documentation "is still not free
of trouble", namely because of its incompatibility with the major
free software licenses.
Critics recommend the use of alternative licenses such as the
share-alike Creative Commons licenses, the
BSD Documentation License,
or (in the Debian case) 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 its texts in 2007,
citing the incompatibility between the two, difficulties in
implementing the GFDL, and the fact that the GFDL "does not allow
for easy duplication and modification", especially for digital
documentation.
DRM clause
The GNU FDL contains the statement:
A criticism of this language is that it is too broad, because it
applies to private copies made but not distributed. This means that
a licensee is not allowed to save document copies "made" in a
proprietary file format or using encryption.
In 2003,
Richard Stallman said
about the above sentence on the debian-legal mailing list:
At any rate, it is likely that laws against computer trespass and
malicious hacking will
protect private copies even if usage of file controls is indeed
forbidden.
Invariant sections
A GNU FDL work can quickly be encumbered because a new, different,
title must be given and a list of previous titles must be kept.
This could lead to the situation where there are a whole series of
title pages, and dedications, in each and every copy of the book if
it has a long lineage. These pages cannot be removed until the work
enters the
public domain after
copyright expires.
Richard Stallman said about
invariant sections on the debian-legal mailing list:
GPL incompatible in both directions
The GNU FDL is
incompatible in
both directions with the GPL: Material under the GNU FDL cannot be
put into GPL code and GPL code cannot be put into a GNU FDL manual.
At the June 22nd and 23rd 2006 international GPLv3 conference in
Barcelona,
Eben Moglen hinted that a
future version of the GPL could be made suitable for
documentation:
Burdens when printing
The GNU FDL requires that licensees, when printing a document
covered by the license, must also include "this License, the
copyright notices, and the license notice saying this License
applies to the Document". This means that if a licensee prints out
a copy of an article whose text is covered under the GNU FDL, he or
she must also include a copyright notice and a physical printout of
the GNU FDL, which is a significantly large document in itself.
Worse, the same is required for the standalone use of just one (for
example, Wikipedia) image.
Wikitravel, a
web site dedicated to
free content
travel guides, chose not to use the GFDL because it considers it
unsuitable for short printed texts.
Transparent formats
The definition of a "transparent" format is complicated, and may be
difficult to apply. For example, drawings are required to be in a
format that allows them to be revised straightforwardly with "some
widely available drawing editor." The definition of "widely
available" may be difficult to interpret, and may change over time,
since, e.g., the open-source
Inkscape
editor is rapidly maturing, but has not yet reached version 1.0.
This section, which was rewritten somewhat between versions 1.1 and
1.2 of the license, uses the terms "widely available" and
"proprietary" inconsistently and without defining them. According
to a strict interpretation of the license, the references to
"generic text editors" could be interpreted as ruling out any
non-human-readable format even if used by an open-source
word-processor; according to a loose interpretation, however,
Microsoft Word .doc format
could qualify as transparent, since a subset of .doc files can be
edited perfectly using
OpenOffice.org, and the format therefore is
not one "that can be read and edited only by proprietary word
processors."
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.
List of projects that use the GFDL
- Most
projects of the Wikimedia Foundation, including Wikipedia
(excluding Wikinews) - On June 15, 2009,
the Section 11 clauses were used to dual-license the content of
these wikis under the Creative Commons Attribution Share-Alike
license.
- PlanetMath
- Citizendium - the project uses GFDL
for articles originally from Wikipedia.
- An Anarchist FAQ
- Marxists Internet
Archive
- SourceWatch
- OpenHistory
- Last.fm - artists descriptions are under
GFDL
- Free On-line
Dictionary of Computing
- The Virginia Commonwealth University Mathematics Department has
begun commercially publishing mathematics texts licensed under the
GDFL, including Linear Algebra by Jim HefferonHefferon, Jim.
Linear Algebra. Virginia Commonwealth University
Mathematics. 2009. ISBN 9780982406212. Paperback. $13.95. and
Abstract Algebra: Theory and Applications by Thomas
Judson.Judson, Thomas. Abstract Algebra: Theory and
Applications. Virginia Commonwealth University Mathematics.
2009. ISBN 9780982406229. Hardcover. $19.95.
See also
References
- Richard Stallman: New Documentation License--Comments Requested
gnu.misc.discuss Newsgroup, 12 September 1999
- FDL 1.3 FAQ
- Some important news from Wikipedia to understand
clearly (Lessig Blog)
-
http://wikimediafoundation.org/wiki/Resolution:License_update
- Richard Stallman: Why
publishers should use the GNU FDL Accessed on 2009-07-17
- GNU project: Frequently Asked Questions about the GNU Licenses:
Why don't you use the GPL for manuals?
- Verizon Settles Open Source Software Lawsuit
(Paul McDougell, InformationWeek, March 17, 2008)
- Why You Shouldn't Use the GNU FDL
- Draft Debian Position Statement about the GNU Free
Documentation License (GFDL). Accessed on 2007-09-25.
- Debian Project: Resolution: Why the GNU Free Documentation License
is not suitable for Debian. Voted February-March 2006.
(Accessed June 20, 2009)
- FLOSS Manuals foundation: License Change June 6, 2007. (Accessed June 20,
2009)
- Richard Stallman (2003-09-06), Re: A possible GFDL compromise. Accessed on
2007-09-25.
- Richard Stallman, (2003-08-23), Re: A possible GFDL compromise. Accessed on
2007-09-25.
- Richard Braakman on Debian-legal about GFDL/GPL
incompatibility
- Transcript of Eben Moglen at the 3rd international
GPLv3 conference; 22nd June 2006: LGPL, like merging electronic
weak. Accessed on 2009-06-20.
- Why the Wikimedia projects should not use GFDL as a
stand alone license for images
- Why Wikitravel isn't GFDL Wikitravel.org
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