Copyleft

The "reversed c" is the copyleft symbol. It has no recognized legal meaning, unlike its counterpart...

...the copyright symbol.

Copyleft describes a group of licenses applied to works such as software, documents, music, and art. Whereas copyright law is seen by the original proponents of copyleft as a way to restrict the right to make and redistribute copies of a particular work, a copyleft license uses copyright law in order to ensure that every person who receives a copy or derived version of a work can use, modify, and also redistribute both the work, and derived versions of the work. Thus, in a non-legal sense, copyleft is the opposite of copyright.

Authors and developers use copyleft with their work to include others in improving and elaborating the work as a continuing process.

History

The concept of copyleft arose when Richard Stallman was working on a Lisp interpreter. Symbolics asked to use the Lisp interpreter, and Stallman agreed to supply them with a public domain version of his work. Symbolics extended and improved the Lisp interpreter, but when Stallman wanted access to the improvements that Symbolics had made to his interpreter, Symbolics refused. Stallman then, in 1984, proceeded to work towards eradicating this kind of behavior, which he named software hoarding.

As Stallman deemed it impractical in the short term to eliminate copyright law and the wrongs he perceived it perpetuating, he decided to work within the framework of existing law; he created his own copyright license, the GNU General Public License (GPL), the first copyleft license. For the first time a copyright holder had taken steps to ensure that the maximal number of rights be perpetually transferred to a program's users, no matter what subsequent revisions anyone made to the original program. This original GPL did not grant rights to the public at large, only those who had already received the program; but it was the best that could be done under existing law. The new license was not at this time given the copyleft label.

Methods for copylefting

Common practice in pursuit of this goal of hassle-free exploitation, copying and distribution of a creation or a work (and its derivatives) is to ship the work subject to a license. Any license that achieves this goal must stipulate that every owner of a copy of the work can:

1. use it without limitation.
2. (re-)distribute as many copies of it as they wish, and
3. modify it in any way they see fit.

These three freedoms, however, do not suffice to ensure that a work that is derived from the creation will be distributed under the same liberal terms; in order for the work to be copylefted, the license has to ensure that the owner of a derived work may only distribute it under a license of the same type.

In addition to restrictions on copying, some other possible impediments to the hassle-free use, distribution and modification of a work that copyleft licences aim to address include:

• making sure that the copyleft license conditions can not be revoked;
• making sure that the work and its derived versions are always made available in a form that facilitates modification. E.g., for software, this facilitating form is considered to be synonymous with the source code.
• devising a more-or-less compulsory system for properly documenting the creation and its modified forms, by way of user's manuals, descriptions, etc.

Copyleft licenses necessarily make creative use of existing rules and laws governing intellectual property; for example, when relying on copyright law (the most common approach), all the people that in any way contributed to the copylefted work become (co-)copyright holders of the work. By the act of granting the license, they deliberately give up some of the rights that normally follow from copyright - for instance, the right to be the unique distributor of copies of the work.

Since they rely on laws governing intellectual property, which vary from one country to another, copyleft licences may also be granted in terms that vary from country to country. For example, in some countries it is acceptable to sell a software product without warranty, in standard GNU GPL style (see articles 11 and 12 of the GNU GPL license version 2), while in most European countries it is not permitted for a software distributor to waive all warranties regarding a sold product. For this reason the extent of such warranties are specified in most European copyleft licenses (see the CeCILL license, a license that allows one to use GNU GPL – art. 5.3.4 of CeCILL – in combination with a limited warranty – art. 9).

Etymology

The term copyleft, according to some sources, came from a message contained in Tiny BASIC, a freely distributed version of BASIC written by Dr. Li-Chen Wang in the late 1970s. The program listing contained the phrases "@COPYLEFT" and "ALL WRONGS RESERVED", puns on "copyright" and "all rights reserved", a phrase commonly used in copyright statements. Richard Stallman himself says the word comes from Don Hopkins, whom he calls a very imaginative fellow, who mailed him a letter in 1984 or 1985 on which was written: "Copyleft—all rights reversed." [1] The term kopyleft with the notation "All Rites Reversed" was also in use in the early 1970s within the Principia Discordia, which may have inspired Hopkins or influenced other usage.

There are definitional problems with the term "copyleft" which contribute to controversy over it. The term originated as an amusing back-formation from the term "copyright", and was originally a noun, meaning the copyright license terms of the GNU General Public License originated by Richard Stallman as part of the Free Software Foundation's work. Thus, "your program is covered by the copyleft" is almost considered to mean the same as the program being GPLed. When used as a verb, as in "he copylefted his most recent version", it is less precise and can refer to any of several similar licenses, or indeed a notional imaginary license for discussion purposes. See also the next section, which goes in detail about some definitional issues.

Types of copyleft and relation to other licenses

Copylefted and non-copylefted open source software

Copyleft is one of the key features distinguishing several types of open source software licenses. Eventually copyleft became the key issue in the ideological strife between the open source movement and the free software movement: copyleft is the short name for a legal framework to ensure that derivatives of a licensed work stay as free as the original (which is not in general a requirement in "open source" licenses). If the licensee of a copylefted work distributes derivative works not under the same (or in some cases similar) copyleft license they will be facing legal consequences; for most copylefted works this implies at least that some provisions of the license are terminated, leaving the (former) licensee without permission to copy and/or distribute and/or publicly display and/or prepare derivative works of the software, etc.

Many open source software licenses, such as those used by the BSD operating systems, the X Window System and the Apache web server, are not copyleft licenses because they do not require the licensee to distribute derivative works under the same license. There is an ongoing debate as to which class of license provides the greater degree of freedom. This debate hinges on complex issues such as the definition of freedom and whose freedoms are more important. It is sometimes argued that the copyleft licenses attempt to maximize the freedom of all potential future recipients of a work (freedom from the creation of proprietary software), while non-copyleft free software licenses maximize the freedom of the initial recipient (freedom to create proprietary software). In a similar vein, the freedom of the recipient (which is restricted by copyleft) may be distinguished from the 'freedom' of the software itself (which is assured by copyleft). See also the section Ideological debate below.

Strong and weak copyleft

The copyleft governing a work is considered to be "stronger", to the extent that the copyleft provisions can be efficiently imposed on all kinds of derived works. "Weak copyleft" refers to licenses where not all derived works inherit the copyleft license; whether a derived work inherits or not often depends on the manner in which it was derived.

"Weak copyleft" licences are generally used for the creation of software libraries, to allow other software to link to the library, and then be redistributed without the legal requirement for the work to be distributed under the library's copyleft license. Only changes to the weak copylefted software itself become subject the copyleft provisions of such a license, not changes to the software that links to it. This allows programs of any license to be compiled and linked against copylefted libraries such as glibc (a standard library required by many programs), and then redistributed without any re-licensing required.

Two examples of free software licenses that uses strong copyleft are the GNU General Public License and the Q Public License. Free software licenses that use "weak" copyleft include the GNU Lesser General Public License (LGPL) [2] and the Mozilla Public License. Examples of non-copyleft free software licenses include the X11 license and the BSD licenses.

Full and partial copyleft

"Full" and "partial" copyleft relate to another issue: Full copyleft is when all parts of a work (except the license itself) can be modified by consecutive authors. Partial copyleft exempts some parts of the work from the copyleft provisions, thus permitting unrestricted modification, or in some other way does not impose all the principles of copylefting on the work. For example, in artistic creation full copylefting is sometimes not possible or desirable (see below).

Share-alike

Many share-alike licenses are partial (or non-full) copyleft licenses. Share-alike, however, imposes the requirement that any freedom that is granted regarding the original work (or its copies), must be granted on exactly exactly the same terms in any derived work: this further implies that any full copyleft license is automatically a share-alike license (but not the other way around!). Instead of using copyright's "all rights reserved" motto, or full copyleft's "all rights reversed", share-alike licenses rather use the "some rights reserved" statement. Some permutations of the Creative Commons license are examples of share-alike licenses.

The ideology

For many people, copyleft is a technique which uses copyright as a means of subverting the restrictions traditionally imposed by copyright on the dissemination and development of knowledge. This approach uses copyleft primarily as a tool in a broadly scaled sniggling operation, whose aim is to permanently reverse such restrictions.

While copyleft is not a term in law, it is seen by proponents as a legal tool in a political and ideological debate over intellectual works. Some see copyleft as a first step in doing away with any kind of copyright law. In the public domain the absence of copyleft-like protection leaves software in an unprotected state. Developers basing their work on public domain originals can spread and sell undocumented binaries without providing the source code. If legal copyright was abolished and without other means, then there would be no method for protecting or enforcing a copyleft license, but the need to do so would also be diminished (except from software hoarding).

Is copyleft "viral"?

Copyleft licenses are sometimes referred to as viral copyright licenses, because any works derived from a copylefted work must themselves be copylefted. This language is often used by those who feel that they may lose out as a result of copyleft provisions. In particular, copyleft works cannot legally be incorporated into works that are to be distributed without source, as is the case with most commercial products, without specific permission from the authors. As a consequence, the use of copyleft in industry is overwhelmingly limited to internal use.

Viral in general refers to anything, especially anything memetic, that propagates itself by attaching itself to something else, regardless of whether the viral components themselves add value to the the object to which it attaches. Many avoid the term viral in the context of legally binding contracts and licenses, because of these negative connotations with computer viruses.

Many people and organisations, including Microsoft, describe the GPL as a "viral license". Supporters of the GPL say that any release of something new under the GPL would create positive feedback network effect, which would result over time in there being an ever-expanding pool of copylefted code.

Additionally, some popular copyleft licenses such as the GPL have an "at-arms-length" clause specifying that copyleft components can interact with non-copyleft components as long as the communication is relatively simple, such as executing a command-line tool with a set of switches. As a consequence, even if one module of an otherwise non-copyleft product is placed under the GPL, it may still be legal for other components to communicate with it in a limited fashion.

Copyleft applied outside the context of copyright licensing for software

Art — documents

Copyleft also inspired the arts (especially where traditional notions of intellectual property are experienced as hampering creativity and/or creative collaboration and/or easy distribution of art creations), with movements like the Libre Society and open-source record labels emerging. For example, the Free Art license is a copyleft license that can be applied to any work of art.

Copyleft licenses for materials other than software include the Creative Commons ShareAlike licenses and the GNU Free Documentation License (abbreviated to GNU FDL, GFDL, or FDL). The GFDL can be used to apply copyleft to works that have no distinguishable source code (while the GPL's requirement to release source code is meaningless when source code is not distinguishable from compiled code or object code or executable code or binary code in a work). The GFDL does distinguish between a "transparent copy" and an "opaque copy", using a different definition than the GPL's "source code" vs. "object code".

In art copyleft has to hinge on broader notions regarding authors' rights, which are even more complex (and more differing between countries) than mere copyright law, see e.g., moral rights, droit d'auteur, intellectual rights and Berne Convention for the Protection of Literary and Artistic Works.

In common with the Creative Commons share-alike licensing system, GNU's Free Documentation License allows authors to apply limitations to certain sections of their work, exempting some parts of their creation from the full copyleft mechanism. In the case of the GFDL, these limitations include the use of invariant sections, which may not be altered by future editors.

These types of partially copyleft licenses can also be used outside the context of art: for GFDL this was even the initial intention, as it was originally created as a device for supporting the documentation of (copylefted) software—the result is however that it can be used for any kind of document.

Many artists copyleft their work on terms requiring that those who copy it and then edit it in some way must credit the initial artist. There are problems with this however - the artist's work may be used in a way that is against his or her will. If the artist is credited, he or she might then seemingly be associated with an undesireable group or ideology.

Patents

Copyleft-like ideas are also increasingly being suggested for patents (so, hinging on a patent law framework instead of on a copyright law framework), such as open patent pools that allow royalty-free use of patents contributed to the pool under certain conditions (such as surrendering the right to apply for new patents that are not contributed to the pool). This has not taken off, perhaps in part because patents are relatively expensive to obtain, whereas copyright is obtained for free.

Since for most copylefted creations the copyleft characteristic is however only secured by copyright law, patenting mechanisms can threaten the copyleft freedoms attached to such creations, when patent law is allowed to overrule copyright (or in any other way limit the free expansion of copylefted creations), which might be the case for the new rules regarding patents developed in the European Union in the early 21st century (see also article on Community Patent). There seems to be no easy answer to such threats, while it is considered that generally communities developing copylefted products have neither the resources nor the organization for complex patenting procedures. However, an organized answer to such issues seems to start emerging from places like Groklaw. Also IBM could be considered by the open source community as rather an ally, when it comes to combining traditional copyright protection for copylefted creations with patented inventions, see: Infoworld article notifying that IBM says it won't assert patents against Linux kernel

Commercial exploitation of copylefted creations

Commercial exploitation of copylefted works differs from traditional commercial exploitation via Intellectual Property Rights (IPR). Exploitation of copylefted works include circumventing the license by gaining only knowledge of the work, or by a model of services--including consultancy and support--for a copylefted work. Generally, financial profit is expected to be much lower in a "copyleft" business than in a business using proprietary works. Firms with proprietary products can make money by exclusive sales, by single and transferable ownership, and lucrative litigation rights over the work.

Development of copylefted industrial products

The competitiveness of copylefted works to proprietary ones is heightened for businesses able to adopt any of a variety of copylefted products that are already written and therefore lowering software development costs. Commercial ventures are able to use their resources to make revenues with the software in other ways, and without the worry of other companies getting an unfair advantage.

Copyleft enables volunteer programmers and organizations to feel involved and contribute to software and feel confident any future derivatives will remain accessible to them, and that their contributions are part of a larger goal, like developing the kernel of an OS. Copylefting software makes clear the intent of never abusing or hiding any knowledge that is contributed. Copyleft also ensures that all contributing programmers and companies can not fork proprietary versions to have create an advantage over another.

The argument for investments in research and development for copyleft businesses may seem weak, by not having exclusivity over the profits gained from the result. Economically, copyleft is considered the only mechanism able to compete with monopolistic firms that rely on financial exploitation of copyright, trademark and patent laws.

Commercialization of copylefted industrial products

Commercial distributors of Linux-based systems (like Red Hat and Mandriva) might have had some ups and downs in finding a successful construction (or Business Model) for setting up such businesses, but in time it was shown to be possible to base a business on a commercial service surrounding a copylefted creation. One well-known example is Mandrake, who was one of the first companies to succeed on the stock market after the implosion of large parts of the IT market in the early 21st century. They also had success in convincing government bodies to switch to their flavor of Linux.

However, apart from rare exceptions like Debian, most Linux distributors don't limit their business to copylefted software. There appears to be no real reason why an exploitation of commercial services surrounding copylefted creations would not be possible in small-scale business, which as a business concept is no more complex than making money with a "public domain" recipe for brewing coffee—successfully exploited by so many cafeteria owners. However, there are few examples so far of SMEs having risked such a leap for their core business. UserLinux, a project set up by Bruce Perens, supports the emergence of such small-scale business based on free software, that is, copylefted or otherwise freely licensed computer programs. The UserLinux website showcases some case studies and success stories of such businesses...

Commercialization of copylefted art

In art the concept of a "commercial service surrounding a copylefted creation" is maybe (even) harder to put in practice than in software development. Public performances could be considered as one of a few possibilities of providing such "services".

The music industry objected to peer-to-peer file exchanging software, but the Electronic Frontier Foundation gave some suggestions to resolve the issue.[3]

Some are more hard on ideas commerce and say: "Intellectual 'property' does not behave like material property. If I give you a physical object I may no longer have use or control of that thing, and may ask for something in return, some payment or barter. But when I give you an idea, I lose nothing. I can still use that idea as I wish. I need ask nothing in return."

Often copylefted artistic creations can be seen to have a (supporting) publicity function, promoting other, more traditionally copyrighted creations by the same artist(s). Artists sticking to an uncompromising copylefting of the whole of their artistic output, could, in addition to services and consultancy, revert to some sort of patronage (sometimes considered as limiting artistic freedom), or to other sources of income, not related to their artistic production (and so mostly limiting the time they can devote to artistic creation too). The least that can be said is that copylefting in art tends toward keeping the art thus produced as much as possible out of the commercial arena—which is considered as an intrinsic positive goal by some.

Some artists use copyleft licenses such as the Creative Commons Attribution-NonCommercial-ShareAlike license that don't allow commercial use. In this way they can choose to sell their creations without having to compete with others selling copies of the same works.

Where copylefted art has a large audience of modest means or a small audience of considerable wealth, the act of releasing the art may be offered for sale. See Street Performer Protocol. This approach can be used for the release of new works, or can be used for the conversion of proprietary works to copylefted works. See Blender.

See also

• All Rites Reversed
• Anti-copyright
• Copynorms
• Copyright-free
• Copyright
• Creative Commons
• Intellectual property
• Intellectual rights
• Magnatune
• Open source record label
• Public domain
• Share-alike
• GNU Free Documentation License
• GNU General Public License

External links

General

• Libre Society website
• FreeCulture.org
• The Electronic Frontier Foundation
• Eye Magazine - Copyleft and Copyright article

Copyleft and software

• www.gnu.org: What is copyleft? (note: although afterwards the GNU copyleft licenses were applied in other fields, this article is basically written from the viewpoint of computer programs)
• Copyleft Mexico website
• a European report (2000) — Report includes section about possible economic models for Free/Libre and Open Source Software.
• Why Free Software's Long Run TCO must be lower — An economic analysis of copylefted software and the software market.
• Linus Torvalds on commercial potential of Linux software (October 2004 interview)

Copyleft applied in artistic creation

• The Free Art license
• Creative Commons website

Copyleft Music artists

• MagnaTune, OnClassical - Music Labels that use copyleft
• Mp3 by MuSiK
• Musique-libre.org - French based copyleft music portal - archive also in English
• [http://www.dance-ù
• Medusa Records
• Ko-operative Recording
• Jamendo - Creative Commons music distributed using BitTorrent and eMule.