Public copyright license
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 licensees or both the licensees and licensors are unlimited. The New York Times has also described them as open copyright licenses, 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 do not limit their licensees. 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. 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. 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.
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.
Varieties of public copyright license
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.
- Herkko A. Hietanen. "A License or a Contract, Analyzing the Nature of Creative Commons Licenses". Social Science Research Network. Retrieved 2012-05-27.
- Jordan Hatcher. "Open Licenses vs Public Licenses". Open Knowledge Foundation Blog. Retrieved 2012-05-27.
- "Travel Site Built on Wiki Ethos Now Bedevils Its Owner". New York Times. Retrieved 2012-09-30.
- "Creative Commons Attribution 3.0 Unported Legal Code". Creative Commons. Retrieved 2012-05-27.
- "About the Licenses". Creative Commons. Retrieved 2012-09-30.