Public copyright license

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A public license or public copyright license is a license by which a licensor can grant additional copyright permissions to licensees and in which either the licensor or both the licensees and licensors are unlimited. The New York Times has also described them as though the Open Knowledge Foundation only uses this term for free content licenses. By applying such a license to a work, copyright holders give permission for others to copy or change their work in ways that would otherwise infringe copyright law provided that the licensees obey the terms and conditions of the license.

Public copyright licenses are reusable, do not limit their licensees.[1] In other words, any person can take advantage of the license. The Creative Commons Developing Nations License is not a public copyright license, because it limits licensees to those in developing nations. According to the Open Knowledge Foundation, to qualify as a public copyright license a license must not limit licensors either.[2] Under this definition,licenses specific to a single licensor (like the UK government’s Open Government License, which would have to be edited to be used by other licensors) do not qualify as public copyright licenses.

Creative Commons licenses are explicitly identified as public licenses.[3] Any person can apply a Creative Commons license to their work, and any person can take advantage of the license to use the licensed work according to the terms and conditions of the relevant license.[4]

Some organisations approve public copyright licenses that meet certain criteria. The Free Software Foundation keeps a list of FSF-approved software licenses and free documentation licenses. The Open Source Initiative keeps a similar list of OSI-approved software licenses. The Open Knowledge Foundation has a list of OKFN-approved licenses for content and data licensing.

Types of copyright license[edit]

The implied license imposed by the Berne Convention, and the public domain (the CC0 license as waiver), are the references for any other public license. Considering all cultural works, as in the Open Definition, the four freedoms summarizes the main differences:

User (licensee) right Berne CC0
0. free access, and freedom to use the work as you wish ("use" includes to run a program or to execute a music score) Partial (some restrictions to execute) Yes
1. freedom to access the "source-code" and use it as you wish, for study or change it for personal use. No Yes
2. freedom to redistribute copies No Yes
2.1 right to quote (freedom to redistribute copies of fragments) Yes, small size. Yes, any size.
3. freedom to distribute copies of your modified versions to others No Yes

The "open licenses" preserve the main freedoms of CC0, but add some reasonable restriction. Labeling by its acronyms, the main restrictions are:

  • BY (attribution): restriction on freedoms 2, 3 or 2.1, the copy must to cite (attribute); give the author or licensor the credits in the manner specified by these.
  • SA (share-alike): restriction on freedoms 2 or 3, the copy must distributed under a license identical to the license that governs the original work (see copyleft).
  • ND (Non-derivative): exclusion of freedom 3.
  • NC (Non-commercial): partial exclusion of freedoms 2 and 3 of commercial purposes.
  • Other: other less usual restrictions on "open licenses".

Varieties of public copyright license[edit]

Free licenses are a popular subset of public copyright licenses. They include free and open source software licenses and free content licenses. To qualify as a libre license, a public copyright license must allow licensees to share and adapt the licensed work for any purpose, including commercial ones. Licenses that purport to release a work into the public domain are a type of libre license.

Share-alike licenses require derivatives of the licensed work to be released under the same license as the original. When a libre license has a share-alike term, it is called a copyleft license. Libre licenses without share-alike terms are sometimes called permissive licenses or copyfree licenses.

The Creative Commons public copyright license suite includes licenses with attribution, share-alike, non-commercial and no-derivatives conditions. It also offers a public domain license and the Founders' Copyright license.

Open supplement licenses permit derivatives of the work (specifically material that supplements the original work) but not duplicates.

Public domain like licenses[edit]

A subset of public copyright licenses which aim for no restrictions at all like public domain ("full permissive"), are public domain-like licenses. The 2000 released WTFPL license is a short public domain like software license.[5] The 2009 released CC0 was created as public domain license for all content with compatibility with also law domains (e.g. Civil law of continental Europe) where dedicating into public domain is problematic. This is achieved by a public domain waiver statement and a fall-back all-permissive license.[6][7] The Unlicense, published around 2010, has a focus on an Anti-copyright message. The Unlicense offers a public domain waiver text with a fall-back public domain-like license inspired by permissive licenses but without attribution.[8][9]

See also[edit]


  1. ^ Herkko A. Hietanen. "A License or a Contract, Analyzing the Nature of Creative Commons Licenses". Social Science Research Network. SSRN 1029366Freely accessible. 
  2. ^ Jordan Hatcher. "Open Licenses vs Public Licenses". Open Knowledge Foundation Blog. Retrieved 2012-05-27. 
  3. ^ "Creative Commons Attribution 3.0 Unported Legal Code". Creative Commons. Retrieved 2012-05-27. 
  4. ^ "About the Licenses". Creative Commons. Retrieved 2012-09-30. 
  5. ^ Version 1.0 license on
  6. ^
  7. ^ Validity of the Creative Commons Zero 1.0 Universal Public Domain Dedication and its usability for bibliographic metadata from the perspective of German Copyright Law by Dr. Till Kreutzer, attorney-at-law in Berlin, Germany
  8. ^ The unlicense a license for no license on by Joe Brockmeier (2010)
  9. ^ The Unlicense on