|Author||Banlu Kemiyatorn, Sam Hocevar|
|FSF approved||Yes |
|GPL compatible||Yes |
|Linking from code with a different licence||Yes|
WTFPL is a permissive free software license, compatible with the GNU GPL.  As a public domain like license, the WTFPL is essentially the same as dedication to the public domain.  It allows redistribution and modification of the work under any terms. The title is an abbreviation of "Do What The Fuck You Want To Public License".
The first version of the WTFPL, released in March 2000, was written by Banlu Kemiyatorn for his own software project.  Sam Hocevar, Debian's former project leader, wrote version 2. 
The WTFPL intends to be a permissive, public-domain-like license. The license is not a copyleft license.  The license differs from public domain in that an author can use it even if they do not necessarily have the ability to place their work in the public domain according to their local laws.  [ failed verification ]
The WTFPL does not include a no-warranty disclaimer, unlike other permissive licenses, such as the MIT License.  Though the WTFPL is untested in court, the official website offers a disclaimer to be used in software source code.  [ better source needed ]
The text of Version 2, the most current version of the license, written by Sam Hocevar: 
DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE Version 2, December 2004 Copyright (C) 2004 Sam Hocevar <firstname.lastname@example.org> Everyone is permitted to copy and distribute verbatim or modified copies of this license document, and changing it is allowed as long as the name is changed. DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 0. You just DO WHAT THE FUCK YOU WANT TO.
do What The Fuck you want to Public License Version 1.0, March 2000 Copyright (C) 2000 Banlu Kemiyatorn (]d). 136 Nives 7 Jangwattana 14 Laksi Bangkok Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Ok, the purpose of this license is simple and you just DO WHAT THE FUCK YOU WANT TO.
To apply the WTFPL to a creative work the author of the work should add a copy of the terms of the license version they wish to use alongside or near the work with which the license is applied. The name of the author named in the license should not be changed unless the name of the license is changed as well—in which case a new version is thereby created.
The WTFPL is not in wide use among open-source software projects; according to Black Duck Software, the WTFPL is used by less than one percent of open-source projects.  Examples include the OpenStreetMap Potlatch online editor,  the video game Liero (version 1.36),  yalu102  and MediaWiki extensions.  More than 5,000 Wikimedia Commons files and more than 24,000 Projects on GitHub were published under the terms of the WTFPL.  
The license was confirmed as a GPL-compatible free software license by the Free Software Foundation, but its use is "not recommended".  In 2009, the Open Source Initiative chose not to approve the license as an open-source license due to redundancy with the Fair License, saying: 
It's no different from dedication to the public domain. Author has submitted license approval request – author is free to make public domain dedication. Although he agrees with the recommendation, Mr. Michlmayr notes that public domain doesn't exist in Europe. Recommend: Reject.
Mr. Michlmayr did not agree with the reasons cited for possible rejection of the WFTPL license since public domain doesn't exist in Europe. [...] Mr. Michlmayr moved that we reject the WFTPL as redundant to the Fair License.
The WTFPL version 2 is an accepted Copyfree license.  It is also accepted by Fedora as a free license and GPL-compatible. 
Some software authors have said that the license is not very serious;  forks have tried to address wording ambiguity and liability concerns.   OSI founding president Eric S. Raymond interpreted the license as written satire against the restrictions of the GPL and other software licenses;  WTFPL version 2 author Sam Hocevar later confirmed that the WTFPL is a parody of the GPL.  Free-culture activist Nina Paley said she considered the WTFPL a free license for cultural works. 
Free software or libre software, infrequently known as freedom-respecting 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, not price; all users are legally free to do what they want with their copies of a free software regardless of how much is paid to obtain the program. Computer programs are deemed "free" if they give end-users ultimate control over the software and, subsequently, over their devices.
The MIT License is a permissive free software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts only very limited restriction on reuse and has, therefore, high license compatibility.
The Apache License is a permissive free software license written by the Apache Software Foundation (ASF). It allows users to use the software for any purpose, to distribute it, to modify it, and to distribute modified versions of the software under the terms of the license, without concern for royalties. The ASF and its projects release their software products under the Apache License. The license is also used by many non-ASF projects.
A software license is a legal instrument governing the use or redistribution of software. Under United States copyright law, all software is copyright protected, in both source code and object code forms, unless that software was developed by the United States Government, in which case it cannot be copyrighted. Authors of copyrighted software can donate their software to the public domain, in which case it is also not covered by copyright and, as a result, cannot be licensed.
Beerware is a tongue-in-cheek term for software released under a very relaxed license. It provides the end user with the right to use a particular program.
The Common Development and Distribution License (CDDL) is a free and open-source software license, produced by Sun Microsystems, based on the Mozilla Public License (MPL). Files licensed under the CDDL can be combined with files licensed under other licenses, whether open source or proprietary. In 2005 the Open Source Initiative approved the license. The Free Software Foundation (FSF) considers it a free software license, but one which is incompatible with the GNU General Public License (GPL).
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, usually including a warranty disclaimer. Examples include the GNU All-permissive License, MIT License, BSD licenses, Apple Public Source License and Apache license. As of 2016, the most popular free-software license is the permissive MIT license.
Alternative terms for free software, such as open source, FOSS, and FLOSS, have been a controversial issue among free and open-source software users from the late 1990s onwards. These terms share almost identical licence criteria and development practices.
This comparison only covers software licenses which have a linked Wikipedia article for details and which are approved by at least one of the following expert groups: the Free Software Foundation, the Open Source Initiative, the Debian Project and the Fedora Project. For a list of licenses not specifically intended for software, see List of free-content licences.
Public-domain software is software that has been placed in the public domain, in other words, software for which there is absolutely no ownership such as copyright, trademark, or patent. Software in the public domain can be modified, distributed, or sold even without any attribution by anyone; this is unlike the common case of software under exclusive copyright, where licenses grant limited usage rights.
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.
License proliferation is the phenomenon of an abundance of already existing and the continued creation of new software licenses for software and software packages in the FOSS ecosystem. License proliferation affects the whole FOSS ecosystem negatively by the burden of increasingly complex license selection, license interaction, and license compatibility considerations.
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 of a piece of software can remove these restrictions by accompanying the software with a software license which grants the recipient these rights. Software using such a license is free software as conferred by the copyright holder. Free-software licenses are applied to software in source code and also binary object-code form, as the copyright law recognizes both forms.
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 license was used for its namesake, the Berkeley Software Distribution (BSD), a Unix-like operating system. The original version has since been revised, and its descendants are referred to as modified BSD licenses.
Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, freedoms refers to the use of the work for any purpose, and the ability to modify, copy, share, and redistribute the work, with or without a fee. Licenses which implement copyleft can be used to maintain copyright conditions for works ranging from computer software, to documents, art, scientific discoveries and even certain patents.
The GNU General Public License is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general use and was originally written by the founder of the Free Software Foundation (FSF), Richard Stallman, for the GNU Project. The license grants the recipients of a computer program the rights of the Free Software Definition. These GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. It is more restrictive than the Lesser General Public License and even further distinct from the more widely used permissive software licenses BSD, MIT, and Apache.
The GNU Free Documentation License is a copyleft license for free documentation, designed by the Free Software Foundation (FSF) for the GNU Project. It is similar to the GNU General Public License, giving readers the rights to copy, redistribute, and modify a work and requires all copies and derivatives to be available under the same license. Copies may also be sold commercially, but, if produced in larger quantities, the original document or source code must be made available to the work's recipient.
A public license or public copyright licenses is a license by which a copyright holder as licensor can grant additional copyright permissions to any and all persons in the general public as licensees. By applying a public license to a work, provided that the licensees obey the terms and conditions of the license, copyright holders give permission for others to copy or change their work in ways that would otherwise infringe copyright law.
Software relicensing is applied in open-source software development when software licenses of software modules are incompatible and are required to be compatible for a greater combined work. Licenses applied to software as copyrightable works, in source code as binary form, can contain contradictory clauses. These requirements can make it impossible to combine source code or content of several software works to create a new combined one.
The GNU All-permissive License is a lax, permissive (non-copyleft) free software license, compatible with the GNU General Public License, recommended by the Free Software Foundation for README and other small supporting files.
[...] the following licenses to be discussed and approved/disapproved by the Board. [...] WTFPL Submission: [...] Comments: It's no different from dedication to the public domain. Author has submitted license approval request -- author is free to make public domain dedication. Although he agrees with the recommendation, Mr. Michlmayr notes that public domain doesn't exist in Europe. Recommend: Reject. [...] Mr. Michlmayr did not agree with the reasons cited for possible rejection of the WFTPL license since public domain doesn't exist in Europe. [...] Mr. Michlmayr moved that we reject the WFTPL as redundant to the Fair License.
The original Liero data and binary files are copyright 1998 Joosa Riekkinen
They are, unless otherwise stated, available under the WTFPL license:
There are at least two not very serious licenses which have essentially the same meaning as public domain. I'm talking about the Beerware license and WTFPL ('Do What The Fuck You Want To' license). I really like these because they pretty well represent my opinion about the legalese bullshit that most licenses are so full of.
… with a CYA clause ….
It’s even clearer that the Do What the Fuck You Want To Public License is a satire. The author is one of those who thinks the Free Software Foundation has traduced the word 'free' by hedging the GNU General Public License about with restrictions and boobytraps in the name of 'freedom' – and he’s got an issue or two with BSD as well. He is poking fun at both camps, not gently at all. His page about the WTFPL is funny-because-it’s-true hilarious, and I admit that I feel a sneaking temptation to start using it myself.
The WTFPL is a parody of the GPL, which has a similar copyright header and list of permissions to modify (i.e. none), see for instance gnu.org/licenses/gpl-3.0.en.html. The purpose of the WTFPL wording is to give more freedom than the GPL does.