GNU Free Documentation License

The GNU Free Documentation License or GFDL (GNU Free Documentation License) is a copyleft license for free content, designed by the Free Software Foundation (FSF) for the GNU project. The complete text can be consulted in the external links.

This license, unlike others, ensures that the material licensed under it is available completely freely, and can be copied, redistributed, modified and even sold as long as the material is maintained under the terms of this same license (GNU GFDL). In the event of a quantity of more than 100 copies being sold, it must be distributed in a format that guarantees future editions (and must include the original text or source code).

This license was designed primarily for manuals, textbooks, and other reference and institutional materials that accompanied the GNU software. However, it can be used in any text-based work, no matter what its content. For example, the free online encyclopedia Wikipedia uses the GFDL (along with the Creative Commons Attribution Share Alike license) for all of its text.

History

The FDL was submitted as a draft in late September 1999 for comment. After revisions, version 1.1 was released in March 2000, and version 1.2 in November. 2002. The current (2008) version of the license is 1.3.

The first discussion draft of the GNU Free Documentation License version 2 was published on September 26, 2006, with a draft of the new simplified GNU Free Documentation License.

The new draft of the GNU FDL includes several improvements, such as new conditions elaborated during the GPLv3 process to improve internationalization, clarifications to help users in applying the license to audio and video, and softened requirements for using extracts from a work.

The new Simplified Free Documentation License does not require invariant title pages or sections. This will provide a simpler licensing option for authors who do not want to use these features of the GNU FDL.

On December 1, 2007, Jimmy Wales announced that a long period of discussion and negotiation between the Free Software Foundation, Creative Commons, the Foundation Wikimedia and others have produced a proposal, supported by both the FSF and Creative Commons, to amend the Free Documentation License in such a way that it allows the possibility for the Wikimedia Foundation to migrate its projects to CC-BY-SA.

Parts of a document

The GFDL license distinguishes between the sections that make up the content of the document itself, and other sections that deal with the same document.

Conditions

Material with the current version of the license may be used for any purpose, as long as the use complies with certain conditions:

• All previous authors of the work must be attributed.
• All changes to work must be recorded.
• All derivative works must be under the same license.
• The full text of the license, invariant sections not modified as defined by the author in his case, and any other denial of added warranty (such as general warning notices to the readers; for example: that the document may not be accurate) and copyright notices from the previous versions must be maintained.
• Technical measures such as DRM (anticopia) cannot be used to control or prevent the distribution or editing of the document.

Secondary sections

The license explicitly separates any type of "document" of "secondary sections", which may not be integrated with the document, but exist as front materials or appendices. Subsections may contain information regarding the relationship of the publisher or author of the subject, but not any subject subject to it. While the document itself is fully editable, and is essentially covered by a license equivalent to (but mutually incompatible with) the GNU General Public License, some of the secondary ones have various restrictions designed primarily to make against the attributions of the previous authors.

Specifically, authors of previous versions have to be acknowledged and certain "invariant sections" specified by the original author and is that its relationship to the subject matter cannot be changed. If the material is modified, the title has to be changed (unless the previous authors give permission to retain the title).

The license also has provisions for manipulating the cover and back cover text of books, as well as "dedications" and the "history", "acknowledgments", "approvals" sections. These features have been added in part to make the license more cost-effective for commercial publishers of software documentation, some of which were consulted during the drafting of the GFDL. The sections of "approvals" they are intended to be used in the official standard for documents, where distribution of modified versions should only be allowed if they are not labeled as just another standard.

Commercial Redistribution

The GFDL requires that the "copying and distribution of the document in any medium (optical, mechanical, acoustic or of any other type), whether non-commercial or commercial, be ensured" and therefore is incompatible with material that precludes commercial use. As mentioned above, the GFDL was designed with commercial publishers in mind, as Stallman explains:

GFDL is understood as a way to have commercial editors in the financing of free documentation without giving up any fundamental freedom. The function of 'cover text', and some other aspects of the license that have to do with the covers, the title page, the history and endorsements, are included to make the license appealing to commercial publishers for books whose authors are paid.

Material that restricts commercial reuse is incompatible with the license and may not be incorporated into the work. However, the incorporation of this type of material may be restricted under United States fair use copyright law (or fair dealing in some other countries) and a license is not required to fall within the GFDL if such fair use is covered by all potential subsequent uses. An example of such liberal and commercial fair use is parody.

Compatibility with the terms of the Creative Commons license

Although the two copyleft licenses work on similar principles, the GFDL license is not compatible with the Creative Commons Attribution-Share Alike license.

However, at the request of the Wikimedia Foundation, version 1.3 adds a time-limited section to allow certain types of websites to use the GFDL, also offer their work under the CC BY-SA license. These exceptions allow a GFDL-based collaborative project with multiple authors to transition to the CC BY-SA 3.0 license, without first obtaining permission from each author, if the work meets a series of conditions:

• The work must have been produced in a "multi-author collaboration site" (MMC); for example, a public wiki.
• If the external content originally published in 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 statement "or any later version", without cover texts or invariant sections. If it was not originally published in a MMC, it can only be relicted if it is added to a MMC before 1 November 2008.

To avoid the clause being used as a general compatibility measure, the certificate only allows change to occur before August 1, 2009. In the 1.3 release, the FSF claimed that all content added before November 1, 2008, to Wikipedia as an example qualified. The Wikimedia Foundation itself after a public consultation, to invoke this process of dual licensing content published under the GFDL license and under the CC BY license -SA in June 2009, and adopted a policy of attribution of all grounds for the use of the contents of the Wikimedia Foundation projects.

Criticism

Many people and groups consider GFDL a non-free license, due in part to its use of "invariant" that cannot be modified or deleted and the well-intentioned but, for some, exaggerated prohibition against digital rights management systems (Digital Rights Management), which also affects some valid uses. On March 16, 2006, the Debian project considered it so, but it already makes an explicit distinction about the existence of invariable sections, which would prevent the inclusion of these documents in the main section of the project.

The GFDL has the same viral nature as the GPL, since modified versions become "infected" with the same license.

Since the license requires the preservation of a series of texts, these may be inconvenient for certain uses. For example, when publishing a book under the GFDL on paper, if its history is very long, you could force a large part of it to be a contribution list. It also creates incompatibilities with other free licences, such as some versions of the Creative Commons licences. The defenders of this type of license justify this by the need to prevent third parties from modifying the document and appropriating it.

In another order of criticism, the Debian project has decided that documents distributed under the GNU Free Documentation License (FDL) are considered free according to the Debian Free Software Guidelines (DFSG) if they do not contain sections invariants. This decision softens the old interpretation of this situation, which said that all documentation released under the GNU FDL should be removed from the archive. Now some of this documentation may be kept on file.

The Free Software Foundation and the Debian project are in talks to resolve these and other objections to the license in a new version.^{[citation needed]} An alternative to The only way that GFDL documents can be included in Debian distributions is that the authors agree to publish their documents under two licences, the GPL and the GFDL.