Read the article at https://www.gnu.org/copyleft/fdl.html
The Free Software Foundation’s version of a copyleft license for software manuals and textbooks, although it specifies that the license is not restricted solely to software-related materials. Published, to some degree, as a response to the open content licenses.
- The purpose is to make a document free (liberated)
- Allows the author to get credit, without being responsible for modifications by others
- Derivative works need to be shared alike
- If there are more than 100 copies distributed then the original must be made available as well
- Used by Wikipedia (+ CC BY-SA) – not compatible without a modified authorship clause.
- Some find it unfree because it allows invariant text which can’t be modified or removed, which doesn’t allow people to make changes.
- Less than reasonable for short printed text – you have to include a hard copy of the license with every printed copy of something licensed with it.
- When is a GNU Free Documentation License better than a Creative Commons license?
Creative Commons Licenses. (2014) http://creativecommons.org/licenses/