what is the concept of copyleft

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.

Full Answer

What is copyleft and how does it work?

Copyleft is a specific license granted under copyright law, and the international statutes governing copyright law are the mechanisms that establish and protect copyleft. Typically, copyleft is a general license agreement granted by a copyright owner permitting anyone to freely use copyrighted property but under specific terms.

What is the difference between copyleft and copyright?

copyleft, license granting general permission to copy and reproduce intellectual property. Where copyright protects society’s interests in invention and creativity by providing individual incentives through copyright control, copyleft protects social interests in knowledge creation by vesting

What are some examples of copyleft and non-copyleft?

Free software licenses that use "weak" copyleft include the GNU Lesser General Public License and the Mozilla Public License. Examples of non-copyleft ("permissive") free software licenses include the X11 license, Apache license and the BSD licenses.

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 is copyleft and how is it different from copyright?

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.

What is difference between open source and copyleft?

Both open source and copyleft allow for source code to be modified and distributed. However, the difference is that with copyleft, the modified product must be distributed with the same copyleft license attached to the original software.

What is copyleft risk?

Copyleft Licensing Problems The problem with copyleft licensing should be clear: anyone can copy and use the program without permission and without attribution. It is considered to be best practices to offer attribution, but it is less common now than it ever was.

How do I use copyleft?

“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.

Is copyleft a form of copyright?

Copyleft is a kind of software license used by copyright owners. Get the details on how this licensing works and what rights it conveys. by Brette Sember, J.D. Most creative works that are placed in a fixed medium can be copyrighted, which means the creator owns the work and no one can use it without permission.

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.

Can you sell copyleft software?

With software that is copyleft, the business will then have the disadvantage that selling licences is rarely possible (because anyone can distribute copies at no financial cost), but the business will have the advantage that their competitors can't incorporate that improved version into a product and then distribute it ...

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.

Who created copyleft?

Don StallmanIn the mid-1980s, Don Stallman coined the term copyleft in a letter he sent to Richard Stallman. Prior to the letter, Stallman created the very first copyleft when working on a Lisp interpreter.

Is copyleft a public domain?

This is called a "share-alike" clause. This is why copyleft isn't the same as public domain. And in the realm of software, it's why BSD and MIT licenses don't count as copyleft licenses. Public domain means that nobody owns rights to a particular work and anybody is free to do whatever they want with it.

Are all open source licenses copyleft?

What is an Open Source Copyleft License? According to the GNU, the founding fathers of the copyleft open source license, copyleft is a method for making a software program free, while requiring that all modified and extended versions of the program also be free, and released under the same terms and conditions.

What is difference between copyright and patent?

A patent protects new inventions, processes, or scientific creations, a trademark protects brands, logos, and slogans, and a copyright protects original works of authorship.

What is an example of a copyright?

Copyright works such as text, images, art works, music, sounds, or movies.

What is the difference between copyright and trademark?

Copyrights primarily protect the rights of people who create literary, dramatic, musical, artistic, and certain other intellectual works (like history tests, and software code). Trademarks protect the use of a company's name and its product names, brand identity (like logos) and slogans.

What is the difference between an author and a copyright owner?

An author or creator may sell you their work, but they will retain ownership of copyright. Unless you made an agreement with the author/creator to transfer copyright, you will not own copyright.

What is copyleft in GNU?

The GNU Project gives this simple definition of copyleft: "the rule that when redistributing the program, you cannot add restrictions to deny other people the central freedoms [of free software]." This can be considered the canonical definition, since the GNU General Public License (GPL) in its various versions remains the most widely-used copyleft license.

How does copyleft differ from permissive?

Where copyleft licenses differ from so-called "permissive" licenses is that copyleft licenses require these same rights to be included in any derivative works. I prefer to think of the distinction in this way: permissive licenses provide the maximum freedom to the immediate downstream developers (including the ability to use the open source code in a closed source project), whereas copyleft licenses provide the maximum freedom through to the end users.

What is copyright?

Before we can understand copyleft, we must first introduce the concept of copyright. Copyleft is not a separate legal framework from copyright; copyleft exists within the rules of copyright. So what is copyright?

What is the most popular copyleft license?

While the GPL family are the most popular copyleft licenses, they are by no means the only ones. The Mozilla Public License and the Eclipse Public License are also very popular. Many other copyleft licenses exist with smaller adoption footprints.

What is the meaning of copyright?

The exact definition varies based on jurisdiction, but the essence is this: the author of a work has a limited monopoly on the copying (hence the term "copyright"), performance, etc. of the work. In the United States, the Constitution explicitly tasks Congress for creating copyright laws in order to "promote the Progress of Science and useful Arts."

Should I choose a copyleft license?

GitHub's choosealicense.com is a good way to find a license that fits your needs. tl;drLegal has plain-language explanations of many common and uncommon software licenses. Also consider the ecosystem that your project lives in. Projects around a specific language or technology will often use the same or similar licenses. If you want your project to be able to play nicely, you may need to make sure the license you choose is compatible.

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.

What is the goal of copyleft?

While copyright law gives software authors control over copying, distribution and modification of their works, the goal of copyleft is to give all users/viewers of the work the freedom to carry out all of these activities. These freedoms (from the Free Software Definition) include:

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.

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 .

What is copyleft in software?

What is Copyleft? Copyleft is a general method for making a program (or other work) free ( in the sense of freedom, not “zero price” ), and requiring all modified and extended versions of the program to be free as well. The simplest way to make a program free software is to put it in the public domain, uncopyrighted.

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.

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.

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.

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.

Why do we use copyright?

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.

Is "copyleft" a verb?

The “left” in “copyleft” is not a reference to the verb “to leave”— only to the direction which is the mirror image of “right”. Copyleft is a general concept, and you can't use a general concept directly; you can only use a specific implementation of the concept.

What is copyleft mechanism?

Copyleft is a licensing mechanism which guarantees that the software will remain free and open source when a downstream distribution occurs. Copyleft ensures that anyone who redistributes FOSS software, irrespective of the fact if this is done with or without modification, has to further pass along the 4 freedoms and the access to the source code to any subsequent users. Therefore, it would not be possible for a middleman in the distribution chain to strip the FOSS software of the 4 fundamental freedoms or make it closed source. It is important to note here that the copyleft mechanism and obligations only apply when software is conveyed externally, i.e. outside of a company or institution.

What is the effect of copyleft?

The direct effect of copyleft is that any immediate downstream developers may lose some of their freedom to operate with a FOSS product but at the same time the broader community of end users clearly benefits as the freedoms and the access to source code get passed to it.

What are the different types of copyleft licenses?

There are two main types of copyleft licenses – strong copyleft and weak copyleft licenses . As the differences between the two may have significant practical impacts on software development projects, they are outlined below in more detail.

What is copyleft in FOSS?

In effect, the main requirement that the copyleft mechanism imposes on a potential user of FOSS software is that when a FOSS product is further distributed, the FOSS license to be used (for both the original program and any modifications) should be the same or compatible (i.e. equally protective) with the initial FOSS license. This requirement brings about a secondary effect that access to the source code (both for the original program and any modifications) cannot be revoked in a subsequent distribution. Thus, copyleft guarantees that FOSS and any modifications to it cannot be turned into proprietary closed source products and the downstream users cannot lose the 4 freedoms and the access to source code.

What is the difference between FOSS and proprietary software?

First, the end user is free to make copies without having to ask for an authorization or pay any royalties to the rightholder. Second, the end user is also free to distribute these copies. Furthermore, the end user is free to modify the software and distribute those modifications, once again without the need for any authorization from the rightholder or the need to pay royalties for these acts.

Is Affero a copyleft license?

The Affero General Public License ( AGPL) is another example of a strong copyleft license. It is based on the GPL license but includes additional terms that specifically deal with distribution of software over a computer network, i.e. software distribution in the cloud. One of the most popular databases for application development in the cloud era – Mongo DB, was licensed under the AGPL up until 2018.

Why do we use copyleft?

Concisely, we just use copyleft to provide a general summary of a key point of the licensing terms, those affecting distribution. Aside from that, it's up to the legalese in the licences.

What is copyleft in licensing?

Copyleft is a general idea, not a specific license. It's used for talking about licenses. It means the general idea of using copyright to ensure open redistribution. Since copyright is usually used for the opposite of that, copyleft is copyright "turned on its head", thus the punning name.

What is the difference between copyleft and permissive licenses?

To elaborate a bit on the legal implications, whilst both permissive and copyleft licenses grant their users freedom along with the code, there is a difference between these two kinds of freedom. Permissive licenses grant freedom to do just about anything with the source code to that one particular user. Copyleft licenses by contrast, tries to secure freedom to it's entire userbase by restricting that particular user's ability to make said source code proprietar y or closed. It achieves this by mandating that any further modification to the copyleft licensed source should be distributed on a similar copyleft license terms. This mandate usually gives the incorrect impression to the initial observer that copyleft licenses are restrictive or "viral" in nature, but a detailed analysis reveals that its not true. Copyleft just tries to secure maximum freedom for the entire community or the user base, not just one user.

What is copyleft in Mozilla?

A simple definition of copyleft is that changes will be released under the same licence. With the Mozilla licence, you can make your own projects under the Mozilla-licenced code, and your own code can be licenced under whatever.

Which came first, copyleft or adobe?

Copyleft came first, by at least 15 years.

Who coined the term "copyleft"?

Copyleft is actually a term coined by Richard Stallman (also called RMS) who is the pioneer of the Free Software Movement which ultimately resulted in today's world where people take using FOSS software so much for granted.

Is copyleft a law?

This means that if you were to say that a project is copyleft, it doesn't mean anything. Under the law, that statement isn't clear, and can't have any meaning, since copyleft is never defined under the law. Think of it as a term in popular culture: people use it, but it doesn't really mean much.

What is copyleft in law?

The core concept of copyleft is that users should have the right to freely use, copy, modify, and distribute works however they want, with one crucial clause: all derivative works must offer the same freedoms to users. Note that copyleft infringement is possible!

What is copyright in art?

A copyright is a legal right bestowed upon creators of original works to dictate how those works can or cannot be copied, modified, and distributed by others. If someone uses or distributes an original work in a way that's contrary to what its creator allows ("infringement"), the creator is entitled to seek legal action.

How many copyleft licenses does Creative Commons have?

The Creative Commons organization offers two copyleft licenses that creators can use when distributing their works.

What is the main idea behind copyright?

The main idea behind copyright is that creators restrict what others can or cannot do with their works and must grant individual permission to do otherwise. Copyleft licenses exist within the legal structure of copyrights. Despite what the name implies, copyleft isn't about abolishing copyrights.

Why is copyright important?

Copyright infringement is one of the biggest problems of the internet age. Never before has it been easier to infringe on intellectual property rights, and never before has it been harder to prevent others from stealing one's hard work.

Is copyleft a permissive license?

2. Copyleft Is More Than Just Permission. A copyleft license isn't the same thing as a permissive license, which grants users the freedom to do ANYTHING they want. Copyleft licenses still impose some demands. The most notable aspect of copyleft licenses is that they require users to distribute derivative works under a license ...

Is copyleft infringement possible?

Note that copyleft infringement is possible! Failing to abide by the rules of a given copyleft license (e.g. GNU General Public License) is grounds for legal action, evidenced by when the Software Freedom Law Center won a lawsuit in 2010 .

Why is copyleft used in programming?

However, because programming is a field where new creations are often built on existing programs, software owners often give users a broad license to alter the work, a permission sometimes called copyleft.

What is copyleft vs copyright?

Copyleft vs. Copyright. Copyleft is a kind of software license used by copyright owners. Get the details on how this licensing works and what rights it conveys. Most creative works that are placed in a fixed medium can be copyrighted, which means the creator owns the work and no one can use it without permission.

How long does a copyleft license last?

Unless stated otherwise, a copyleft license lasts as long as the copyright on the original work is in place. Once the work passes into the public domain, which happens automatically 70 years after the death of the creators, anyone can use the work, even without a license. An example of a copyleft license is the GNU General Public License (GPL), which only allows the altered work to be distributed under the original licensing terms. Although a copyleft license encourages derivative works, it also ensures that the works and all their future forms remain free.

Why is it important to register your copyright?

If you have created software, it is a good idea to register your copyright so you can protect it and your creative interests.

Is Microsoft Office a copyright?

This type of software, also sometimes called closed-source software, retains its full copyright, meaning no reuse is permitted. The source code is usually secret and the owner might limit the number of computers you can use the software on for each license you buy. Microsoft Office is a common example of proprietary software.

What Is Copyright?

See more on opensource.com

What Is Copyleft?

Copyleft in Software

Copyleft in Non-Software

Should I Choose A Copyleft License?

Overview

History

An early use of the word copyleft was in Li-Chen Wang's Palo Alto Tiny BASIC's distribution notice "@COPYLEFT ALL WRONGS RESERVED" in June 1976. Tiny BASIC was not distributed under any formal form of copyleft distribution terms, but it was presented in a context where source code was being shared and modified. In fact, Wang had earlier contributed edits to Tiny BASIC Extended before writing his own BASIC interpreter. He encouraged others to adapt his source co…

Copyleft principles

Copyleft application

Types and relation to other licenses

Debate and controversy

Symbol

See also