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. This is microsofts copyleft license, which only allows you to sublicense with other licenses that comply with this one. A form of licensing that encourages the distribution of software at no charge for noncommercial uses. Most gpl version 2 software is actually licensed as gpl version 2 or any later version, or. In the gnu project, the specific distribution terms that we use for most software are contained in the gnu general public license. Copyleft licensing is favourable for software coders. It was created by michael stutz after his interest in applying gnustyle copyleft to nonsoftware works, which later came to be called open content. Non copyleft licenses will dominate for large oss projects. In other words, a copyleft license prevents people from taking freely available material, altering it and then selling it as proprietary material. Nov 10, 2010 in other words, a copyleft license prevents people from taking freely available material, altering it and then selling it as proprietary material. Korean the principles of communityoriented gpl enforcement the gnu general public license gpl is the principal copyleft license. Many free software licenses are not copyleft licenses because they do not require the licensee to distribute derivative works under the same license. Here you will find an archive of all the copyleft and open source licenses that have been published in the past. Highlights initial oss license choice is dependent on the level of oss developmental efforts.
Some free software licenses dont establish an obligation of licensing derivative work in the same terms of the original work license. Optimal license choice not necessarily the preferred license of the oss. After opting into the copyleft licence, the source code is readily available, and it allows others to modify and develop the code. Greater the efforts to develop the oss, less likely that its license is restrictive. Creative commons is a nonprofit corporation dedicated to making it easier for people to share and build upon the work of others, consistent with the rules of. Explore the world of open source, and discover how to choose a licensing model for your app, in this foundations of programming course with attorney and technologist john v. Noncopyleft licenses will dominate for large oss projects.
There are variations, of coursethe lgpl, for example, is a weak copyleft. Microsoft reciprocal license msrl explained in plain. From beerware licensing, where you need to buy a beer for the open source programmer if you see them in a bar, to the finetuned and legallycurated berkeley software distribution bsd license, we have it. Under most conditions, semirestrictive licenses will be preferred to the extremes. Copyleft definition of copyleft by the free dictionary. Copyleft compliance projects software freedom conservancy 990 have joined. Jun 24, 2006 most copylefted software is issued under the gnu general public license gpl, which was the first copyleft license and by far the most commonly used license for free software. The free software component that is part of the composite is only available under a strong copyleft license no permissive license, no duallicense. Copyleft is a distinguishing feature of some free software licenses. The internet provides a suitable platform for sharing and developing source code and open collaboration results in faster and more efficient development. Files that are entirely your own work stay unaffected, but your users must receive access to any files that contain code under the microsoft reciprocal license. The primary project currently on this site is a tutorial book entitled copyleft and the gnu general public license.
It can be applied to documents to make the open content for the public. What are some examples of sharealikecopyleft licenses. When one hears about free software, the first thing that comes to mind might be no cost. From beerware licensing, where you need to buy a beer for the open source programmer if you see them in a bar, to the finetuned and legallycurated berkeley software distribution bsd license, we have it all. Opensource licenses allow software to be freely used, modified, or shared, while respecting the original programmers authorship and intent. Copyleft is a general concept, and you cant use a general concept directly.
The second form of copyleft licensing is the creative commons sharealike license. It is not the opposite of, but its purpose is the opposite of the purpose of the frequently seen type of license which uses to forbid changing, giving, or selling something. The gnu general public license is often called the gnu gpl for short. Free software is software whose source code is freely available to anyone to use for any purpose, including studying, copying, modifying, extending and giving away. Gnu general public license, version 3 spdx short identifier. The free software component does not allow some exception to strong copyleft i.
Free software licenses can be divided into two broad categories. This form of copyleft is more prominent in the art community. While this is often true, the term free software as used by the free software foundation originators of the gnu project and creators of the gnu general public license is intended to mean free as in freedom rather than in the sense. Copyleft is a name for a type of a license for free content or free software. The design science license is a strong copyleft license that can apply to any worknot only software or documentation, but also to literature, artworks, music, photography, and video. Software libre y software libre no protegido con copyleft by.
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