Public-domain-equivalent license are

license A license (or licence) is an official permission or permit to do, use, or own something (as well as the document of that permission or permit). A license is granted by a party (licensor) to another party (licensee) as an element of an agreeme ...

s that grant

public-domain The public domain (PD) consists of all the creative work to which no exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly waived, or may be inapplicable. Because those rights have expired, ...

-like rights and/or act as

waiver A waiver is the voluntary relinquishment or surrender of some known right or privilege. Regulatory agencies of state departments or the federal government may issue waivers to exempt companies from certain regulations. For example, a United St ...

s. They are used to make copyrighted works usable by anyone without conditions, while avoiding the complexities of attribution or

license compatibility License compatibility is a legal framework that allows for pieces of software with different software licenses to be distributed together. The need for such a framework arises because the different licenses can contain contradictory requirement ...

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 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. 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

In 2000, the "Do What the Fuck You Want To Public License" (

WTFPL WTFPL is a permissive free software license. As a public domain like license, the WTFPL is essentially the same as dedication to the public domain The public domain (PD) consists of all the creative work A creative work is a manifest ...

) 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 In contract law, a warranty is a promise which is not a condition of the contract or an innominate term: (1) it is a term "not going to the root of the contract",Hogg M. (2011). ''Promises and Contract Law: Comparative Perspectives''p. 48 Cambrid ...

disclaimer A disclaimer is generally any statement intended to specify or delimit the scope of rights and obligations that may be exercised and enforced by parties in a legally recognized relationship. In contrast to other terms for legally operative langua ...

. In 2016, according to Black Duck Software, the WTFPL was used by less than 1% of

FOSS Fos or FOSS may refer to: Companies *Foss A/S, a Danish analytical instrument company * Foss Brewery, a former brewery in Oslo, Norway *Foss Maritime, a tugboat and shipping company Historic houses * Foss House (New Brighton, Minnesota), United ...

projects. In 2009,

Creative Commons Creative Commons (CC) is an American non-profit organization and international network devoted to educational access and expanding the range of creative works available for others to build upon legally and to share. The organization has release ...

released

CC0 A Creative Commons (CC) license is one of several public copyright licenses that enable the free distribution of an otherwise copyrighted "work".A "work" is any creative material made by a person. A painting, a graphic, a book, a song/lyrics ...

, which was created for

compatibility Compatibility may refer to: Computing * Backward compatibility, in which newer devices can understand data generated by older devices * Compatibility card, an expansion card for hardware emulation of another device * Compatibility layer, compon ...

with jurisdictions where dedicating to public domain is problematic, such as

continental Europe Continental Europe or mainland Europe is the contiguous continent of Europe, excluding its surrounding islands. It can also be referred to ambiguously as the European continent, – which can conversely mean the whole of Europe – and, by ...

. This is achieved by a public-domain waiver statement and a fall-back all-

permissive license A permissive software license, sometimes also called BSD-like or BSD-style license, is a free-software license which instead of copyleft protections, carries only minimal restrictions on how the software can be used, modified, and redistributed, ...

, for cases where the waiver is not valid. The

Free Software Foundation The Free Software Foundation (FSF) is a 501(c)#501(c)(3), 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985, to support the free software movement, with the organization's preference for software being distributed ...

and the

Open Knowledge Foundation Open Knowledge Foundation (OKF) is a global, non-profit network that promotes and shares information at no charge, including both content and data. It was founded by Rufus Pollock on 20 May 2004 in Cambridge, UK. It is incorporated in England an ...

approved CC0 as a recommended license to dedicate content to the public domain. The FSF and the

Open Source Initiative The Open Source Initiative (OSI) is the steward of the Open Source Definition, the set of rules that define open source software. It is a California public-benefit nonprofit corporation,_with_501(c)(3).html" ;"title="110. - 6910./ref> is a type o ...

, 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 The Fedora Project is an independent project to co-ordinate the development of Fedora Linux, a Linux-based operating system, operating with the vision of "''a world where everyone benefits from free and open source software built by inclusive, w ...

's software packages placed CC0 as the 17th most popular license. The

Unlicense The Unlicense is a public domain equivalent license for software which provides a public domain waiver with a fall-back public-domain-like license, similar to the CC Zero for cultural works. It includes language used in earlier software projects a ...

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. The BSD Zero Clause License removes half a sentence from the

OpenBSD OpenBSD is a security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by forking NetBSD 1.0. According to the website, the OpenBSD project em ...

template license, leaving only an unconditional grant of rights and a warranty disclaimer. It is listed by the

Software Package Data Exchange Software Package Data Exchange (SPDX) is an open standard for software bill of materials (SBOM). SPDX allows the expression of components, licenses, copyrights, security references and other metadata relating to software. Its original purpose w ...

as the Zero Clause BSD license, with the SPDX identifier 0BSD. It was first used by Rob Landley in

Toybox Toybox is a free and open-source software implementation of over 200 Unix command line utilities such as '' ls'', '' cp'', and '' mv''. The Toybox project was started in 2006, and became a 0BSD licensed BusyBox alternative. Toybox is used for mos ...

and is OSI-approved. The MIT No Attribution License, a variation of the MIT License, was published in 2018 and has the identifier MIT-0 in the

SPDX Software Package Data Exchange (SPDX) is an open standard for software bill of materials (SBOM). SPDX allows the expression of components, licenses, copyrights, security references and other metadata relating to software. Its original purpose w ...

License List.

Reception

In the

free-software Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...

community, there has been some controversy over whether a

public domain The public domain (PD) consists of all the creative work A creative work is a manifestation of creative effort including fine artwork (sculpture, paintings, drawing, sketching, performance art), dance, writing (literature), filmmaking, ...

dedication constitutes a valid

open-source license An open-source license is a type of license for computer software and other products that allows the source code, blueprint or design to be used, modified and/or shared under defined terms and conditions. This allows end users and commercial compa ...

. 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, a position that faced opposition by

Daniel J. Bernstein Daniel Julius Bernstein (sometimes known as djb; born October 29, 1971) is an American German mathematician, cryptologist, and computer scientist. He is a visiting professor at CASA at Ruhr University Bochum, as well as a research professor of ...

and others. In 2012, Rosen changed his mind, accepted

as an open-source license, and admitted that, contrary to his previous claims, copyright can be waived away. In 2011, the

added CC0 to its

free software licenses A free-software license is a notice that grants the recipient of a piece of software extensive rights to modify and redistribute that software. These actions are usually prohibited by copyright law, but the rights-holder (usually the author) ...

and called it "the preferred method of releasing software in the public domain". In February 2012, when the CC0 license was submitted to the

for approval, 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 patent A software patent is a patent on a piece of software, such as a computer program, libraries, user interface, or algorithm. Background A patent is a set of exclusionary rights granted by a state to a patent holder for a limited period of time, u ...

s. As a result, Creative Commons withdrew their submission, and the license is not currently approved by the OSI. In July 2022, the

deprecated CC0 for software code for the same reasons, but will still allow its use for non-code content. In June 2020, following a request for legacy approval, OSI formally recognized the Unlicense as an approved license meeting the OSD.

Google Google LLC () is an American multinational technology company focusing on search engine technology, online advertising, cloud computing, computer software, quantum computing, e-commerce, artificial intelligence, and consumer electronics. ...

does not allow its employees to contribute to projects under public domain equivalent licenses like the Unlicense and CC0, while allowing contributions to

0BSD BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD lice ...

licensed and US government PD projects.

Notes

References

{{Reflist , refs = {{cite web , 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 {{cite web , 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 {{cite web , url = https://creativecommons.org/weblog/2009/03/11/13304 , title = 11/17: Lulan Artisans Textile Competition , date = 18 June 2009 {{cite web , 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 {{cite web , url = https://creativecommons.org/weblog/entry/27081 , title = Using CC0 for public domain software , date = 15 April 2011 , publisher =

, access-date = 2011-05-10 {{cite web , url = https://www.gnu.org/licenses/license-list.html , title = Various Licenses and Comments about Them , publisher =

GNU Project The GNU Project () is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and computing devices by collaborati ...

, access-date = 2015-04-04 {{cite web , url = http://opendefinition.org/licenses/ , title = licenses , work =

The Open Definition The Open Definition is a document published by the Open Knowledge Foundation (OKF) (previously Open Knowledge International) to define openness in relation to data and content. It specifies what licences for such material may and may not stipula ...

{{cite web , 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 {{cite web , 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 {{cite web , 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 {{cite web , 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 {{cite web , 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 GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking system, bug tracking, software feature requests, task man ...

Permissive software licenses Public domain Public copyright licenses Terms of service

Licenses

Reception

See also

Notes

References