Copyleft is a specific license granted under copyright law, and the international statutes governing copyright law are the mechanisms that establish and protect copyleft.

Copyleft is a form of licensing, and can be used to maintain copyright conditions for works ranging from computer software, to documents, to art, to scientific discoveries and instruments in medicine. In general, copyright law is used by an author to prohibit recipients from reproducing, adapting, or distributing copies of their work.

Copyleft, is the practice of offering people the right to freely distribute copies and modified versions of a work with the stipulation that the same rights be preserved in derivative works created later. Copy left software licenses are considered protective or reciprocal, as contrasted with permissive free-software licenses.

Under copy left, an author must give every person who receives a copy of the work permission to reproduce, adapt, or distribute it, with the accompanying requirement that any resulting copies or adaptations are also bound by the same licensing terms.

Copyleft itself probably began in the work of MIT computer expert Richard Stallman. In 1983, Stallman started an open-source programming project called GNU (a reflexive acronym for “GNU’s Not Unix”) and created the first general public license to govern the use of GNU, keeping it and its derivatives open and freely available. Many consider the concept of copyleft to be a return to the earliest ideas of intellectual property, which treat ideas and their specific forms as a common heritage. Given that intellectual creations build on what has come before and shape what comes next, copy left is seen as a bridging mechanism to encourage the growth of social knowledge and common good.

Copyleft is a strategy of utilizing copyright law to pursue the policy goal of fostering and encouraging the equal and inalienable right to copy, share, modify and improve creative works of authorship. Copy left (as a general term) describes any method that utilizes the copyright system to achieve the aforementioned goal. Copyl eft as a concept is usually implemented in the details of a specific copyright license, such as the GNU General Public License (GPL) and the Creative Commons Attribution Share Alike License. Copyright holders of creative works can unilaterally choose these licenses for their own works to build communities that collaboratively share and improve those copyleft creative works.

A copyleft license allows users of the software to copy, make changes, and then distribute their adaptation. However, the user is not permitted to copyright their new version, which means they cannot profit from their adapted work by licensing it.

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 by adhesion contract that the works and all their future forms remain free.

A permissive license allows users to copy, modify, and distribute the content. This differs from copyright licensing in that permissive license allows users to copyright and license their adaptations, whereas copyleft does not.

There are usually some minimal requirements placed on use, such as that attribution be given to the original creators. Because of this, some copyright privileges are retained, meaning the content is not in the public domain. An example of a permissive license is the MIT license, which allows reuse only if the original MIT license terms and copyright notice are included and requires the original creators to be credited in any future use. The web-development framework Ruby on Rails is an example of software with a permissive license.

The most permissive of software licenses, an open-source license puts content directly into the public domain. No copyright is retained to the work and anyone can use, change, distribute, and copyright their own adaptations—and even profit from their work. LibreOffice, a free alternative to Microsoft Office, is an example of open-source software.

Here at BEST GURU INFO we give everybody permission and the right to copy and redistribute anything on our website. If you can use it — COPY IT.   It would be super nice if you give us credit for the material that you copy, i.e. “FROM BESTGURU.INFO” after all, that is what the internet is all about — sharing ideas and information. Enjoy!