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 licenseesor 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. 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.

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:

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Wikipedia