The GFDL and you
Welcome to The GFDL and You, a learning project where Wikiversity participants explore the license that is applied to all the text added by editors to Wikiversity pages. GFDL stands for "GNU Free Documentation License" and is a form of "copyleft" licensing. This learning project covers the meaning and significance of "copyleft" licensing for Wikiversity participants.
Copyright law allows an author to control what other people do with the author's work. For example, if you write a story, copyright laws can be used to limit the ability of others to sell copies of your story. A copyright holder can use legally binding licenses to give permission to some people to copy a copyrighted work in a specific way, for example, exchanging the right to distribute copies of a story in exchange for payments to the author. Copyleft is a way of using copyright law to eliminate possible restrictions on how a copyrighted work is copied and used by others.
When you edit a Wikiversity webpage, you automatically grant other people to right to copy and modify and re-use what you wrote because you agree to license what you wrote under the terms of the GNU Free Documentation License. Every Wikiversity edit page says, "You agree to license your contributions under the GFDL," in the small space between the text editing window and the "save button".
Do you retain copyright? 
Question. Do you retain copyright for what you contribute to Wikiversity?
Answer. Yes, but at the same time, by licensing your work under the GFDL you have explicitly given away many of the "rights" and restrictions that copyright laws are often used to enforce. If, at some time in the future, you found someone using your GFDL-licensed work without having properly licensed it or attributed it to you, then you can take legal action. See the sections below on "attribution" and "share-alike".
If you have questions about copyright and copyleft, edit this section and ask your question, below.
Uses of the GFDL 
As the name implies, the GNU Free Documentation License was originally created for use with software documentation manuals. However, the GFDL can be used to license a "manual or other work, in any medium". For example, the GFDL has long been used for images, audio files and video files. For information about how uploaded files can be licensed under the GFDL, see: Wikiversity:Uploading files.
Other licensing options 
Some people do not like to use the GFDL for non-textual works. If you do not want to use the GFDL for uploaded images, audio files and video files, you can use the accepted Creative Commons licenses. The Creative Commons Attribution-ShareAlike License has the same intent as the GFDL. You can also place media files that you create in the Public domain.
The GFDL is a form of licensing that requires attribution. The GFDL specifies that anyone who distributes copies of a work that is licensed under the GFDL should "Preserve the section Entitled 'History'" and list "at least five of the principal authors of the Document". Wikiversity webpages have an associated "history page" that lists every edit to the webpage. In practice, copies of a Wikiversity webpage content should provide a link back to the original webpage where the list of editors can be found.
The GFDL is a Share-alike license. This means that you are allowed to make modified versions of a work that uses the GFDL, but you must also license your modified version under the GFDL. Thus, the GFDL grants others the right to copy and modify a work and also requires that the same freedoms be preserved in modified versions.
Commercial re-use 
The GFDL makes no distinction between commercial and noncommercial copying and re-use of a work. Wikiversity content can be copied, modified, and redistributed, either commercially or non-commercially, so long as the new version grants the same freedoms to others and acknowledges the authors of the Wikiversity webpage used as a source of content (a direct link back to the webpage satisfies our author credit requirement).
Other licenses used at Wikiversity 
As discussed above and specified by the terms of the GFDL, all copyrighted text added to Wikiversity webpages by the copyright holder is licensed under the GFDL. In the United States, all original works that meet basic standards of originality are automatically copyrighted.
In addition to text, the Wikiversity website also includes images, audio files and video files. The GFDL can be used to license media files you create; see Wikiversity:Uploading files. Another license that is also allowed for media files is the Creative Commons licenses Attribution-ShareAlike license, which is very similar to the GFDL. See Template:Cc-by-sa-3.0. Wikiversity also can include content that is in the Public domain. See: Template:PD. The MediaWiki software that is used to generate Wikiversity webpages is licensed under the GPL. You can upload screen shots of Wikiversity pages and use Template:Wikiversity-screenshot. Other templates for file licensing are in Category:Document copyright tags.
See also: Fair use.
Copyright violation 
When you edit a Wikiversity page, in the small space between the text editing window and the "save button" it says, "Content that violates any copyright will be deleted." Wikiversity does not allow any content that is not freely available for future copying and re-use. If you add someone else's work to the Wikiversity website, you must be sure that it is freely available for future copying and re-use. See: Wikiversity:Deletion policy.