public-domain-equivalent license
{{Short description|License that waives all copyright}}
{{multiple image
| direction = vertical
| width = 140
| image1 = WTFPL logo.svg
| caption1 = WTFPL license logo, a public-domain-like license
| image2 = Cc-zero.svg
| caption2 = CC0 license logo, a copyright waiver and public-domain-like license{{cite web
| url = https://creativecommons.org/about/downloads
| title = Downloads
| publisher = Creative Commons
| date = 2015-12-16 |df=dmy
| access-date = 2015-12-24
}}
| image3 = PD-icon-black.svg
| caption3 = Unlicense logo, a copyright waiver and public-domain-like license
}}
Public-domain-equivalent license are licenses that grant public-domain-like rights and/or act as waivers. They are used to make copyrighted works usable by anyone without conditions, while avoiding the complexities of attribution or license compatibility that occur with other licenses.
No permission or license is required for a work truly in the public domain, such as one with an expired copyright; such a work may be copied at will. Public domain equivalent licenses exist because some legal jurisdictions{{which|date=January 2019}} do not provide for authors to voluntarily place their work in the public domain, but do allow them to grant arbitrarily broad rights in the work to the public.{{cite web |last=Hoppe-Jänisch |first=Daniel |date=2015-05-19 |df=dmy |title=IP Assignment Clauses in International Employment Contracts |publisher=Lexology |location=London |page=9 |url=https://www.lexology.com/library/document.ashx?g=365c8b4a-efe5-45c7-872f-88ca68042d7a |access-date=2025-06-09 |quote=European copyright systems provide for a stronger connection between the copyright and the author of the protected work. This makes sense if one considers that even though the German {{lang|de|Urheberrecht}} or the French {{lang|fr|droit d'auteur}} are often translated as copyright, the literal translation is author's right. It comprises not only proprietary rights but also moral rights. In many European jurisdictions, only the proprietary rights are assignable; in others, copyrights, including the proprietary rights, cannot be assigned at all but authors may only grant others a license to exploit the protected work. Moral rights are usually not assignable and can be waived only to a limited extent.}}
The licensing process also allows authors, particularly software authors, the opportunity to explicitly deny any implied warranty that might give someone a basis for legal action against them. While there is no universally agreed-upon license, several licenses aim to grant the same rights that would apply to a work in the public domain.
Licenses
= WTFPL =
In 2000, the "Do What the Fuck You Want To Public License" (WTFPL) was released as a public-domain-equivalent license for software. It is distinguished among software licenses by its informal style and lack of a warranty disclaimer. In 2016, according to Black Duck Software,{{NoteTag|1. MIT License: 26%; 2. GNU General Public License (GPL) 2.0: 21%; 3. Apache License 2.0: 16%; 4. GNU General Public License (GPL) 3.0: 9%; 5. BSD License 2.0 (3-clause, New or Revised) License: 6%; 6. GNU Lesser General Public License (LGPL) 2.1: 4%; 7. Artistic License (Perl): 4%; 8. GNU Lesser General Public License (LGPL) 3.0: 2%; 9. ISC License: 2%; 10. Microsoft Public License: 2%; 11. Eclipse Public License (EPL): 2%; 12. Code Project Open License 1.02: 1%; 13. Mozilla Public License (MPL) 1.1: < 1%; 14. Simplified BSD License (BSD): < 1%; 15. Common Development and Distribution License (CDDL): < 1%; 16. GNU Affero General Public License v3 or later: < 1%; 17. Microsoft Reciprocal License: < 1%; 18. Sun GPL With Classpath Exception v2.0: < 1%; 19. DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE: < 1%; 20: CDDL-1.1: < 1%}} the WTFPL was used by less than 1% of FOSS projects.
= CC0 =
In 2009, Creative Commons released CC0, which was created for compatibility with jurisdictions where dedicating to public domain is problematic, such as continental Europe.{{Citation needed|date=July 2016}} This is achieved by a public-domain waiver statement and a fall-back all-permissive license, for cases where the waiver is not valid. The Free Software Foundation and the Open Knowledge Foundation approved CC0 as a recommended license to dedicate content to the public domain. The FSF and the Open Source Initiative, however, do not recommend the usage of this license for software due to inclusion of a clause expressly stating it does not grant patent licenses. In June 2016 an analysis of the Fedora Project's software packages placed CC0 as the 17th most popular license.{{NoteTag|There are total 19,221 approved packages in Fedora repository as found on 20.06.2016, among those 1124 were dead packages. […] From the above chart it is clear that the GPL family is the highest used (I had miscalculated it as MIT before).The other major licenses are MIT, BSD, the LGPL family, Artistic (for Perl packages), LPPL (foe texlive packages), ASL. Apart from these licenses there are projects who has submitted themselves in to Public Domain and that number is 517 and 11 packages have mentioned their license as Unlicense.}}
= Unlicense =
The Unlicense software license, published around 2010, offers a public-domain waiver text with a fall-back public-domain-like license, inspired by permissive licenses but without an attribution clause. In 2015 GitHub reported that approximately 102,000 of their 5.1 million licensed projects, or 2%, use the Unlicense.{{NoteTag|1= 1. MIT: 44.69%; 2. Other: 15.68%; 3. GPLv2: 12.96%; 4. Apache: 11.19%; 5. GPLv3: 8.88%; 6. BSD 3-clause: 4.53%; 7. Unlicense: 1.87%; 8. BSD 2-clause: 1.70%; 9. LGPLv3: 1.30%; 10. AGPLv3: 1.05% (30 mill * 2% * 17% = 102k)}}
= 0BSD =
The BSD Zero Clause License{{cite web |url = https://opensource.org/licenses/0BSD |title = Zero-Clause BSD {{!}} Open Source Initiative |website = opensource.org |access-date = 2018-12-18 }}, published in 2013[https://github.com/landley/toybox/commit/ee86b1d8e25cb0ca9d418b33eb0dc5e7716ddc1e Toybox GitHub commit], removes half a sentence from the ISC license, leaving only an unconditional grant of rights and a warranty disclaimer.[https://landley.net/toybox/license.html Toybox is released under the following "zero clause" BSD license] by Rob Landley It is listed by the Software Package Data Exchange as the Zero Clause BSD license, with the SPDX identifier 0BSD.[https://spdx.org/licenses/0BSD.html BSD Zero Clause License] It was first used by Rob Landley in Toybox and is OSI-approved.
= MIT-0 =
The MIT No Attribution License, a variation of the MIT License, was published in 2018 and has the identifier MIT-0 in the SPDX License List.{{cite web|url=https://spdx.org/licenses/MIT-0.html|title=MIT No Attribution|publisher=SPDX Working Group|website=spdx.org}}
Reception
In the free-software community, there has been some controversy over whether a public domain dedication constitutes a valid open-source license. In 2004, lawyer Lawrence Rosen argued in the essay "Why the public domain isn't a license" that software could not truly be given into public domain,{{cite web|url=http://www.rosenlaw.com/lj16.htm |title=Why the public domain isn't a license |author=Lawrence Rosen |author-link=Lawrence Rosen (attorney) |date=2004-05-25 |access-date=2016-02-22 |publisher=rosenlaw.com}} a position that faced opposition by Daniel J. Bernstein and others.[https://cr.yp.to/publicdomain.html Placing documents into the public domain] by Daniel J. Bernstein on cr.yp.to: "Most rights can be voluntarily abandoned ('waived') by the owner of the rights. Legislators can go to extra effort to create rights that can't be abandoned, but usually they don't do this. In particular, you can voluntarily abandon your United States copyrights: 'It is well settled that rights gained under the Copyright Act may be abandoned. But abandonment of a right must be manifested by some overt act indicating an intention to abandon that right. See Hampton v. Paramount Pictures Corp., 279 F.2d 100, 104 (9th Cir. 1960).'" (2004). In 2012, Rosen changed his mind, accepted CC0 as an open-source license, and admitted that, contrary to his previous claims, copyright can be waived away.{{cite web |url=https://lists.opensource.org/pipermail/license-review/2012-March/001679.html |quote=The case you referenced in your email, Hampton v. Paramount Pictures, 279 F.2d 100 (9th Cir. Cal. 1960), stands for the proposition that, at least in the Ninth Circuit, a person can indeed abandon his copyrights (counter to what I wrote in my article) – but it takes the equivalent of a manifest license to do so. :-) [...] For the record, I have already voted +1 to approve the CC0 public domain dedication and fallback license as OSD compliant. I admit that I have argued for years against the "public domain" as an open source license, but in retrospect, considering the minimal risk to developers and users relying on such software and the evident popularity of that "license", I changed my mind. One can't stand in the way of a fire hose of free public domain software, even if it doesn't come with a better FOSS license that I trust more. |author=Lawrence Rosen |date=2012-03-08 |publisher=opensource.org |title=[License-review] [License-discuss] CC0 incompliant with OSD on patents, (was: MXM compared to CC0) |access-date=2016-02-22 |archive-url=https://web.archive.org/web/20160312093735/https://lists.opensource.org/pipermail/license-review/2012-March/001679.html |archive-date=2016-03-12 |url-status=dead |author-link=Lawrence Rosen (attorney) }}
In 2011, the Free Software Foundation added CC0 to its free software licenses and called it "the preferred method of releasing software in the public domain"{{cite web |url=https://creativecommons.org/weblog/entry/27081 |title=Using CC0 for public domain software |date=April 15, 2011 |publisher=Creative Commons |access-date=May 10, 2011}}{{cite web |url=https://www.gnu.org/licenses/license-list.html |title=Various Licenses and Comments about Them |publisher=GNU Project |access-date=April 4, 2015 }} – the Foundation then reviewed its position specifically for softwares.
In February 2012, when the CC0 license was submitted to the Open Source Initiative for approval,{{cite web
|url = http://projects.opensource.org/pipermail/license-review/2012-February/
|title = OSI recognition for Creative Commons Zero License?
|author = Carl Boettiger
|work = In the Open Source Initiative Licence review mailing list
|publisher = opensource.org
|access-date = February 1, 2012
|url-status = dead
|archive-url = https://web.archive.org/web/20130926193810/http://projects.opensource.org/pipermail/license-review/2012-February/
|archive-date = September 26, 2013
}} controversy arose over a clause which excluded any relevant patents held by the copyright holder from the scope of the license. This clause was added with scientific data in mind rather than software, but some members of the OSI believed it could weaken users' defenses against software patents. As a result, Creative Commons withdrew their submission, and the license is not currently approved by the OSI.{{cite web| url = http://projects.opensource.org/pipermail/license-review/2012-February/000231.html| title = CC {{sic|withd|rawl|nolink=y}} of CC0 from OSI process|archive-url=https://web.archive.org/web/20150906005825/https://lists.opensource.org/pipermail/license-review/2012-February/000231.html|archive-date=2015-09-06| author = Christopher Allan Webber |work=In the Open Source Initiative Licence review mailing list| access-date = February 24, 2012}}{{cite web
| url = http://opensource.org/faq#cc-zero
| title = What about the Creative Commons "CC0" ("CC Zero") public domain dedication? Is that Open Source?
| author = The Open Source Initiative FAQ
| access-date = May 25, 2013
|publisher=opensource.org
}} In July 2022, the Fedora Project deprecated CC0 for software code for the same reasons, but will still allow its use for non-code content.{{Cite web |last=Francisco |first=Thomas Claburn in San |title=Fedora sours on CC 'No Rights Reserved' license |url=https://www.theregister.com/2022/07/25/fedora_sours_on_creative_commons/ |access-date=2022-07-26 |website=www.theregister.com |language=en}}
In June 2020, following a request for legacy approval, OSI formally recognized the Unlicense as an approved license meeting the OSD.{{cite web
| url=http://lists.opensource.org/pipermail/license-review_lists.opensource.org/2020-June/004890.html
| archive-date=September 8, 2020
| archive-url=https://web.archive.org/web/20200908144433/http://lists.opensource.org/pipermail/license-review_lists.opensource.org/2020-June/004890.html
| title=[License-review] Request for legacy approval: The Unlicense
| date=June 16, 2020
| first=Pamela
| last=Chestek
}}
Google does not allow its employees to contribute to projects under public domain equivalent licenses like the Unlicense and CC0, while allowing contributions to 0BSD licensed and US government PD projects.{{cite web |url=https://opensource.google/docs/patching/ |access-date=2020-09-29 |title=Open Source Patching }}
See also
Notes
{{NoteFoot}}
References
{{Reflist
|refs =
| url = http://anonscm.debian.org/viewvc/pkg-wmaker/trunk/COPYING.WTFPL?revision=2&view=markup
| title = Version 1.0 license
| website = anonscm.debian.org
| access-date = 2016-06-19
| archive-url = https://web.archive.org/web/20130602181949/http://anonscm.debian.org/viewvc/pkg-wmaker/trunk/COPYING.WTFPL?revision=2&view=markup
| archive-date = 2013-06-02
| url-status = dead
}}
| url = http://www.blackducksoftware.com/resources/data/top-20-licenses
| title = Top 20 licenses
| publisher = Black Duck Software
| date = 31 May 2016
| access-date = 2016-05-31
| archive-url = https://web.archive.org/web/20160719043600/https://www.blackducksoftware.com/top-open-source-licenses
| archive-date = 2016-07-19
}}
| url = https://rd-alliance.org/sites/default/files/cc0-analysis-kreuzer.pdf
| title = 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
| author = Till Kreutzer
}}
| url = https://creativecommons.org/weblog/entry/27081
| title = Using CC0 for public domain software
| date = 15 April 2011
| publisher = Creative Commons
| access-date = 2011-05-10
}}
| url = https://www.gnu.org/licenses/license-list.html
| title = Various Licenses and Comments about Them
| publisher = GNU Project
| access-date = 2015-04-04
}}
| url = http://opendefinition.org/licenses/
| title = licenses
| work = The Open Definition
}}
| url = https://blog.creativecommons.org/2013/12/27/creative-commons-4-0-by-and-by-sa-licenses-approved-conformant-with-the-open-definition/
| title = Creative Commons 4.0 BY and BY-SA licenses approved conformant with the Open Definition
| author = Timothy Vollmer
| website = creativecommons.org
| date = 27 December 2013
}}
| url = https://anweshadas.in/software-licenses-in-fedora-ecosystem/
| title = Software Licenses in Fedora Ecosystem
| date = 22 June 2016
| access-date = 2016-06-27
| website = anweshadas.in
| author = Anwesha Das
}}
|url = http://ostatic.com/blog/the-unlicense-a-license-for-no-license
|title = The Unlicense: A License for No License
|website = ostatic.com
|author = Joe Brockmeier
|date = 2010
|url-status = dead
|archive-url = https://web.archive.org/web/20160324154539/http://ostatic.com/blog/the-unlicense-a-license-for-no-license
|archive-date = 2016-03-24
}}
| url = http://unlicense.org
| title = The Unlicense
| website = unlicense.org
| access-date = 2020-05-12
| archive-url = https://web.archive.org/web/20180708180735/http://unlicense.org/
| archive-date = 2018-07-08
| url-status = dead
}}
| url = https://github.com/blog/1964-license-usage-on-github-com
| title = Open source license usage on GitHub.com
| date = 9 March 2015
| author = Ben Balter
| access-date = 2015-11-21
| website = github.com
}}
}}
Category:Permissive software licenses