Creative Commons, a non-profit organization, has released a variety of copyright licenses to increase the amount of free cultural works and open content. All Creative Commons licenses allow verbatim distribution, but they may have other restrictions. The latest version of the licenses is the 4.0 version. A list of the six supported licenses are here, and they all start with "Creative Commons":
- Attribution
: Works under this license may be freely modified and sold without the author's permission, but the author must be credited like they want to, to the extent supported by the license (copyright notice provided, indication of any changes, not unlawfully implying endorsement from the author et cetera). This license is free.
- Attribution-ShareAlike: Same as Attribution, but derivative works must be under the same or compatible license. Not only a free license, but also the only copyleft one out of them, thanks to its combination of a ShareAlike clause with having no restrictions on use, not even forbidding commercial use, but it does force derivative works to allow such use.
- Attribution-NonCommercial: Same as Attribution, but forbids commercial use, as in use primarily intended for financial gain. What NonCommercial really means is controversial, since there is a grey area between commercial and non-commercial use (Do donations and ads count as commercial use? Is it only commercial if intentionally so?). According to a report by Creative Commons, there are variations on what this is expected to mean. There are also cases of creators having their own biases on the definition. Because of its restriction on commercial use, this license is non-free, and reasons against noncommercial licenses have been brought up, like incompatibility with a large body of free content.
- Attribution-NonCommercial-ShareAlike: Like Attribution-NonCommercial, but derivative works must be under the same or compatible license. This license is non-free.
- Attribution-NoDerivatives: Like Attribution, but derivative works are forbidden. As of the 4.0 version, modifications may be made as long as they are not shared. This license is non-free, along with other licenses that forbid derivative works.
- Attribution-NonCommercial-NoDerivatives: The strictest license of them all, forbidding both commercial use and derivative works, but otherwise still allowing verbatim distribution, making it not be "all rights reserved". This license is non-free.
By the way, Creative Commons licenses cannot be revoked, and grant the same freedoms to everyone, so use it once to grant some freedoms, and those freedoms are permanently granted.
TV Tropes is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License by default.
Whether this is a license or not depends, but this tool called "Creative Commons CC0 1.0 Universal Public Domain Dedication", or CC0 for short, lets copyright holders release their works into the Public Domain, or at least as close to it as possible, in case if certain rights like moral rights cannot be revoked.
See also Copyright, since this is about letting copyright holders control which freedoms they want to grant other users in a world where default copyright laws are strict. Also a case of Information Wants to Be Free.
Subpages of Creative Commons-licensed works:
- Attribution
- Attribution-ShareAlike
- Attribution-NonCommercial
- Attribution-NonCommercial-ShareAlike
- Attribution-NoDerivatives
- Attribution-NonCommercial-NoDerivatives
