GNU Free Documentation License (GFDL)
- Domain of Application: Content.
The GNU Free Documentation License is a copyleft license - which means that derivative works must be made available under the same or a similar license.
The creators of the license recommend that it is used “principally for works whose purpose is instruction or reference.” Its most prominent user is Wikipedia.
The GFDL is only considered conformant if you
- don’t use invariant Sections or cover texts
- don’t include an “Acknowledgements” or “Dedications” section
- amend the DRM restriction (section 2) to be less broad (for example restricting to the requirement that the work is available without TPMs)
Please see for more information:
How to apply
To use the GFDL, include a copy of the full text of the license and the following notice in your work:
Copyright (c) [YEAR] [YOUR NAME]. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".