What's the difference between copyleft and the GNU GPL?
Copyleft is a general concept, and you can't use a general concept directly; you can only use a specific implementation of the concept. In the GNU Project, the specific distribution terms that we use for most software are contained in the GNU General Public License. The GNU General Public License is often called the GNU GPL for short.
What is the previous version of GNU GPL?
GNU General Public License (GPL) version 2. Archived from the original on 20 July 2017. Retrieved 20 July 2017. ... This is the previous version of the GNU GPL: a free software license, and a copyleft license. ... GPLv2 is, by itself, not compatible with GPLv3.
What free software licenses are compatible with the GPL?
FSF maintains a list of GPL- compatible free software licenses containing many of the most common free software licenses, such as the original MIT/X license, the BSD license (in its current 3-clause form), and the Artistic License 2.0.
What is the difference between the GPL and the LGPL?
The GNU Lesser General Public License (LGPL) was created to have a weaker copyleft than the GPL, in that it does not require custom-developed source code (distinct from the LGPL'ed parts) to be made available under the same license terms.
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Is GPL a strong copyleft license?
The GNU General Public License is an example of a license implementing strong copyleft. A stronger copyleft license is the AGPL, which requires the publishing of the source code for software as a service use cases.
What is an example of copyleft?
Copyleft is a term, usually referring to a license, used to indicate that such license requires that redistribution of said work is subject to the same license as the original. Examples of copyleft licenses are the GNU GPL (for software) and the Creative Commons SA (Share Alike) licenses (for works of art).
What type of license is GPL?
copyleft licenseThe GNU General Public License is a free, copyleft license for software and other kinds of works. The licenses for most software and other practical works are designed to take away your freedom to share and change the works.
What licenses are copyleft?
What is a Copyleft License? Copyleft licenses allow software to be modified and re-distributed by anyone as long as the same rights are also preserved in derivative works.
Is Linux a copyleft?
Linux is covered by what is known as the GNU General Public License, or GPL. The GPL, which is sometimes referred to as a "copyleft" license, was developed for the GNU project by the Free Software Foundation.
Is copyleft same as open source?
Copyleft is a subset of open source. Contrary to what the term might imply, copyleft is not the opposite of copyright. In fact, copyleft is grounded in the concept of copyright, without which copyleft couldn't exist.
Is GPL the same as open source?
GPL is the acronym for GNU's General Public License, and it's one of the most popular open source licenses. Richard Stallman created the GPL to protect the GNU software from being made proprietary.
Is GPL open source?
GNU General Public License (GPL) is among the most popular open source licenses.
What is meant by copyleft?
Copyleft is the idea and the specific stipulation when distributing software that the user will be able to copy it freely, examine and modify the source code, and redistribute the software to others (free or priced) as long as the redistributed software is also passed along with the copyleft stipulation.
What is a strong copyleft license?
Copyleft licenses come in two flavors: strong and weak. This distinction turns on how much new or adjacent code is subject to the copyleft license. Under a strong copyleft license like GPL, if you redistribute a program that includes GPL code written by others, you must make your entire program available under GPL.
What is non copyleft?
Non-copyleft licenses permit the code to be incorporated in software or programs that are distributed under some other license, including a proprietary one. Most common non-copyleft licenses: Apache License Version 2.0. BSD license. MIT license.
Is Apache a copyleft?
Is the Apache considered copyleft? Copyleft licenses require the derivative works or modified versions of existing software to be released under the same license. The Apache License doesn't have any such requirements. It's a permissive license.
What is meant by copyleft?
Copyleft is the idea and the specific stipulation when distributing software that the user will be able to copy it freely, examine and modify the source code, and redistribute the software to others (free or priced) as long as the redistributed software is also passed along with the copyleft stipulation.
Why is it called copyleft?
Proprietary software developers use copyright to take away the users' freedom; we use copyright to guarantee their freedom. That's why we reverse the name, changing “copyright” into “copyleft.” Copyleft is a way of using the copyright on the program.
What is difference between copyright and copyleft?
1. Copyright is the right that enable you to prevent unauthorized copying or selling of your work. Whereas Copyleft is a method using which you can modify the software or documentation and distribute it back to the open-source community. 2.
Is Common Public license copyleft?
In computing, the Common Public License (CPL) is a free software / open-source software license published by IBM....Common Public License.AuthorIBMGPL compatibleNoCopyleftLimitedLinking from code with a different licenceYes7 more rows
What is a GPL container?
Consider the case of a container in which both GPL code and proprietary code might coexist and execute. A container is, in essence, an isolated userspace stack. In the OCI container image format, code is packaged as a set of filesystem changeset layers, with the base layer normally being a stripped-down conventional Linux distribution without a kernel. As with the userspace of non-containerized Linux distributions, these base layers invariably contain many GPL-licensed packages (both GPLv2 and GPLv3), as well as packages under licenses considered GPL-incompatible, and commonly function as a runtime for proprietary as well as open source applications. The "mere aggregation" clause in GPLv2 (as well as its counterpart GPLv3 provision on "aggregates") shows that this type of combination is generally acceptable, is specifically contemplated under the GPL, and has no effect on the licensing of the two programs, assuming incompatibly licensed components are separate and independent.
Is there a license compliance obligation for sharing container images?
Open source license compliance obligations may arise when sharing container images. But there’s nothing technically different or unique about containers that changes the nature of these obligations or makes them harder to satisfy. With respect to copyleft scope, containerization should, if anything, ease the concerns of the extra-cautious.
What is the GNU GPL?
In the GNU Project, the specific distribution terms that we use for most software are contained in the GNU General Public License. The GNU General Public License is often called the GNU GPL for short. There is also a Frequently Asked Questions page about the GNU GPL. You can also read about why the FSF gets copyright assignments from contributors.
What is a copyleft in GNU?
So instead of putting GNU software in the public domain, we “copyleft” it. Copyleft says that anyone who redistributes the software, with or without changes, must pass along the freedom to further copy and change it. Copyleft guarantees that every user has freedom. Copyleft also provides an incentive for other programmers to add to free software.
What is version 3 of the GPL?
Version 3 of the Lesser GPL is built as an exception added to GPL version 3, making the compatibility automatic. If you would like to copyleft your program with the GNU GPL or the GNU LGPL, please see the license instructions page for advice. Please note that you must use the entire text of the license you choose.
Why is copyleft important?
Copyleft guarantees that every user has freedom. Copyleft also provides an incentive for other programmers to add to free software. Important free programs such as the GNU C++ compiler exist only because of this. Copyleft also helps programmers who want to contribute improvements to free software get permission to do so.
Why is GNU copyleft?
So instead of putting GNU software in the public domain, we “copyleft” it. Copyleft says that anyone who redistributes the software, with or without changes, must pass along the freedom to further copy and change it. Copyleft guarantees that every user has freedom.
What is a FDL?
The GNU Free Documentation License (FDL) is a form of copyleft intended for use on a manual, textbook or other document to assure everyone the effective freedom to copy and redistribute it, with or without modifications, either commercially or noncommercially.
How to copyleft a program?
To copyleft a program, we first state that it is copyrighted; then we add distribution terms, which are a legal instrument that gives everyone the rights to use, modify, and redistribute the program's code, or any program derived from it, but only if the distribution terms are unchanged. Thus, the code and the freedoms become legally inseparable.
What is a GPL license?
GPL was the first copyleft license for general use. Historically, the GPL license family has been one of the most popular software licenses in the free and open-source software domain. Prominent free software programs licensed under the GPL include the Linux kernel and the GNU Compiler Collection (GCC).
What is GPL software?
The GNU General Public License ( GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the freedom to run, study, share, and modify the software. The licenses were originally written by Richard Stallman, founder of the Free Software Foundation (FSF), for the GNU Project, and grant the recipients of a computer program the rights of the Free Software Definition. The GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. This is in distinction to permissive software licenses, of which the BSD licenses and the MIT License are widely used, less restrictive examples. GPL was the first copyleft license for general use.
What was the GPL version 2?
The second version of the license, version 2, was released in 1991. Over the following 15 years, members of the free software community became concerned over problems in the GPLv2 license that could let someone exploit GPL-licensed software in ways contrary to the license's intent. These problems included tivoization (the inclusion of GPL-licensed software in hardware that refuses to run modified versions of its software), compatibility issues similar to those of the Affero General Public License, and patent deals between Microsoft and distributors of free and open-source software, which some viewed as an attempt to use patents as a weapon against the free software community.
Why is GPL incompatible with Mac?
The problem lies in the right "To make a copy for your neighbour", as this right is violated by digital rights management systems embedded within the platform to prevent copying of paid software. Even if the application is free in the App Store in question, it might result in a violation of that app store's terms.
When was the GPL version 2 released?
By 1990, it was becoming apparent that a less restrictive license would be strategically useful for the C library and for software libraries that essentially did the job of existing proprietary ones; when version 2 of the GPL (GPLv2) was released in June 1991 , therefore, a second license – the GNU Library General Public License – was introduced at the same time and numbered with version 2 to show that both were complementary. The version numbers diverged in 1999 when version 2.1 of the LGPL was released, which renamed it the GNU Lesser General Public License to reflect its place in the philosophy. The GPLv2 was also modified to refer to the new name of the LGPL, but its version number remained the same, resulting in the original GPLv2 not being recognised by the Software Package Data Exchange (SPDX).
Can GPLv3 be combined with GPLv2?
However, GPLv3 software could only be combined and share code with GPLv2 software if the GPLv2 license used had the optional "or later" clause and ...
Who created the GPL?
The GPL was written by Richard Stallman in 1989, for use with programs released as part of the GNU project. The original GPL was based on a unification of similar licenses used for early versions of GNU Emacs (1985), the GNU Debugger, and the GNU C Compiler. These licenses contained similar provisions to the modern GPL, but were specific to each program, rendering them incompatible, despite being the same license. Stallman's goal was to produce one license that could be used for any project, thus making it possible for many projects to share code.
What is copyleft?
Copyleft is a term that first appeared in the Tiny BASIC program written by Dr. Li-Chen Wang in 1976. Widely considered the first freeware, the program’s distribution included copyleft and all wrongs reserved as part of the licensing text, an obvious statement of opposition to copyright. Stallman took note and used the idea of copyleft to formulate the first GNU General Public License (GPL) in 1988.
What is copyleft in open source software?
Permissive licenses allow collaborative projects to become proprietary if required, which is something expressly prohibited by copyleft. Copyleft intends to enforce user freedom during all stages of a code base’s lifecycle.
What are the most popular copyleft licenses?
The most popular copyleft license remains the GPL published by Stallman in 1988. Since then, GPL has evolved, and the latest version is the GPLv3. To clarify previous legal challenges, the Free Software Foundation (FSF) also published additions to the GPL, including the Lesser General Public License (LGPL) and the Affero General Public License (AGPL) .
What is a Microsoft reciprocal license?
Microsoft Reciprocal License – This license only allows for sublicensing products with other licenses that comply with the Microsoft Reciprocal License (Ms-RL). Files that remain the user’s work can remain closed, but all other files should be open and available to other users.
What is the Mozilla Public License?
Mozilla Public License – Currently in version 2, the Mozilla Public License (MPL) requires developers to make source code available on release but doesn’t enforce the same requirements on other proprietary components.
What does GPLv3 mean?
In the context of GPL, it means any product built on a previous user’s work will remain accessible to other users in the future. Although different versions of GPL can comply with other proprietary licenses, the GPLv3 will force teams to make every aspect of their code available to the public.
What is open software license?
Open Software License – A simple to understand license for a wide range of projects. Like the AGPL, users of the Open Source License 3.0 will need to disclose their source code when distributing the software.
Why do people use copyleft licenses?
Such programs are often published with a copyleft license simply to ensure that subsequent users can also freely use modified versions of that program. This is especially true for creators who wish to prevent "open source hijacking", or the act of reusing open sourced code and then adding extra restrictions to it, an action prevented by copyleft licensing the software. Some creators feel that preventing commercial enterprises from absorbing and selling their product is another incentive.
Which free software licenses use copyleft?
Free-software licenses that use "weak" copyleft include the GNU Lesser General Public License and the Mozilla Public License . The most well-known free-software license using strong copyleft is the GNU General Public License .
Why are copyleft licenses considered reciprocal?
For this reason, copyleft licenses are also known as reciprocal licenses- any modifiers of a copyleft-licensed work are expected to reciprocate the author's action of copyleft-licensing the software by also copyleft-licensing any derivatives they might have made. Because of this requirement, copyleft licenses have also been described as "viral" due to their self-perpetuating terms.
What is copyleft in publishing?
One of the main restrictions imposed by copyleft is that derived works must also be released under a compatible copyleft license.
How does copyleft affect the economy?
The presence of quality copyleft software can force proprietary software developers to increase the quality of their software to compete with free software. This may also have the effect of preventing monopolies in areas dominated by proprietary software. However, competition with proprietary software can also be a reason to forego copyleft. The Free Software Foundation recommends that when "widespread use of the code is vital for advancing the cause of free software," allowing the code to be copied and used freely is more important than a copyleft.
What is copyleft in art?
Copyleft is the practice of granting the right to freely distribute and modify intellectual property with the requirement that the same rights be preserved in derivative works created from that property. Copyleft in the form of licenses can be used to maintain copyright conditions for works ranging from computer software, to documents, art, scientific discoveries and even certain patents.
Where did the copyleft label come from?
The new license was not at this time given the copyleft label. Richard Stallman stated that the use of "Copyleft" comes from Don Hopkins, who mailed him a letter in 1984 or 1985, on which was written: "Copyleft – all rights reversed.".
Overview
The GNU General Public License (GNU GPL or simply GPL) 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 …
History
The GPL was written by Richard Stallman in 1989, for use with programs released as part of the GNU project. The original GPL was based on a unification of similar licenses used for early versions of GNU Emacs (1985), the GNU Debugger, and the GNU C Compiler. These licenses contained similar provisions to the modern GPL, but were specific to each program, rendering them incomp…
Terms and conditions
The terms and conditions of the GPL must be made available to anybody receiving a copy of the work that has a GPL applied to it ("the licensee"). Any licensee who adheres to the terms and conditions is given permission to modify the work, as well as to copy and redistribute the work or any derivative version. The licensee is allowed to charge a fee for this service or do this free of charg…
Derivations
The text of the GPL is itself copyrighted, and the copyright is held by the Free Software Foundation.
The FSF permits people to create new licenses based on the GPL, as long as the derived licenses do not use the GPL preamble without permission. This is discouraged, however, since such a license might be incompatible with the GPL and causes a perceived license proliferation.
Linking and derived works
According to the FSF, "The GPL does not require you to release your modified version or any part of it. You are free to make modifications and use them privately, without ever releasing them." However, if one releases a GPL-licensed entity to the public, there is an issue regarding linking: namely, whether a proprietary program that uses a GPL library is in violation of the GPL.
This key dispute is whether non-GPL software can legally statically link or dynamically link to GPL l…
Legal status
The first known violation of the GPL was in 1989, when NeXT extended the GCC compiler to support Objective-C, but did not publicly release the changes. After an inquiry they created a public patch. There was no lawsuit filed for this violation.
In 2002, MySQL AB sued Progress NuSphere for copyright and trademark infringement in United States district court. NuSphere had allegedly violated MySQL's copyright by linking MySQL's GPL…
Compatibility and multi-licensing
Code licensed under several other licenses can be combined with a program under the GPL without conflict, as long as the combination of restrictions on the work as a whole does not put any additional restrictions beyond what GPL allows. In addition to the regular terms of the GPL, there are additional restrictions and permissions one can apply:
Text and other media
It is possible to use the GPL for text documents instead of computer programs, or more generally for all kinds of media, if it is clear what constitutes the source code (defined as "the preferred form of the work for making changes in it"). For manuals and textbooks, though, the FSF recommends the GNU Free Documentation License (GFDL) instead, which it created for this purpose. Nevertheless, the Debian developers recommended (in a resolution adopted in 2006) to …