This may be included in asf products much like the weak copyleft list above. Here you will find an archive of all the copyleft and open source licenses that have been published in the past. Fink recapped the negative effects of license proliferation and addressed projects that use their choice of license as hostile act against the competition. Copyleft licences try to ensure that the code contributed by open. The internet provides a suitable platform for sharing and developing source code and open collaboration results in faster and more efficient development. Kuhn i have probably spent more time dealing with the implications and realworld scenarios of copyleft in the embedded device space than anyone. 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. If you choose to use or modify code released under this license, it must be provided under the same license. Contributor means each entity that creates or contributes to the creation of modifications. Electronic distribution mechanism means a mechanism generally accepted in the software development community for the electronic transfer of data. Gpl is provided through the free software foundation, a nonprofit corporation that works to provide free software for the gnu project. The most wellknown free software license that uses strong copyleft is the gnu general public license. Doug leas concurrent library is public domain, but contains some sun files which are not public domain. What is the difference between the eclipse public license and ibms common public license cpl.
Its a copyleft license and also the most popular one. Copyleft license legal definition of copyleft license by. All opensource licenses allow users to reproduce and redistribute the work in source or binary form, and to redistribute modified versions in source or binary form. Immediately recognized as a free software license by the free software foundation and approved as an open source license by the open source initiative, mpl 2. So if you use a library in a project, the rest of the project doesnt need to be distributed under that license, but the library does. What are the important differences between the most common. As explained in the previous section, a copyleft license means downstream projects cannot add additional restrictions on the use of the software. The most common copyleft license in use is the gpl, the gnu general public license, which maintains the biggest market share among all open source licenses. This short guide gives a brief introduction to copyleft licenses, an important kind of open software license.
Users are permitted to engage in copying and distributing ed materials. Original code means source code of computer software code which is described in the source. The mozilla public license and the eclipse public license are also very popular. For questions about the public domain, please see this faq entry. With strong copyleft license, the gpl family, you are obligated to reuse the same licence in case of redistribution of copies or derivatives on both source and binaries. X11 license, is a very permissive noncopyleft license that allows everyone to basically use the solicensed code for whatever you want as long as you keep the message, and know that the software comes without warranty of any kind. The gnu general public license gpl is a free, copyleft license used primarily for software. You must include a notice, specified in exhibit a, in each source file. The sun public license spl is a software license that applies to some open source software released by sun microsystems it has been approved by the free. Asf 3rd party license policy the apache software foundation.
Copyleft simple english wikipedia, the free encyclopedia. Copyleft compliance projects software freedom conservancy. Commercial use means distribution or otherwise making the covered code available to a third party. Sun used to release its free software open source projects under its sun public license spl before it turned to rely upon the cddl in 2004. The following licenses qualify as free software licenses, and are compatible with the gnu gpl gnu general public license gpl version 3. Kuhn this blog post was also crossposted to my blog at software freedom conservancy. Copyleft is free software license requiring authors to permit some of their work to be reproduced. Copyleft is a framework that permits ongoing sharing of a published work, with clear permissions that both grant and defend its users freedoms in contrast to other free licenses that grant freedom but dont defend. A copyleft license uses to forbid forbidding changing, giving, or selling something. Two property regimes for software development may be distinguished. We are using cookies for the best presentation of our site. It may be included in binary form within an apache product if the inclusion is appropriately labeled. Sun begins releasing java under the gpl free software.
Gnu general public license gpl the gnus general public license is the most popular open source license around. A derivative of the mozilla public license used for some sun microsystems software. On account of the nature of copyleft license, any software which is created based on any gpl component has to be released to open source. Many other copyleft licenses exist with smaller adoption footprints. Some people use the pejorative name viral license for a copyleft license. Understanding copyleft licenses at a high level unlocks a world of new software, from linux to wordpress to libreoffice and more permissive and copyleft. If you offer a license that isnt a copyleft license, the copyleft provisions collapse and the software is now available to all under a noncopyleft, hyperpermissive foss license.
The sun public license spl is a software license that applies to some opensource software released by sun microsystems such as netbeans before the 5. The principles of communityoriented gpl enforcement. He then ended the session with an extended appeal to move the opensource software industry away from permissive licenses like apache 2. A copyleft license is a license that grants the permission to freely use, modify, and redistribute the covered intellectual propertybut only if the original license remains intact, both for the. Within corporations, on the one hand, a private regime obtains which excludes all outsiders from access to a firms software assets. Copyleft license means any license that requires, as a condition of use, modification or distribution of copyleft materials, that such copyleft materials, or other software or content incorporated into, derived from, used, or distributed with such copyleft materials. Copyleft is a general concept, and you cant use a general concept directly. I hope you will donate now before the challenge match period ends so that you can support work like this that im. With law, authors have complete control over their materials. The cddl license is considered by sun now oracle to be spl version 2. According to this gnu project page, regarding microsoft public license mspl. Well, sun, before oracles acquisition, sought to collaborate with the classpath community.
Selling exceptions depends fundamentally on using a copyleft license, such as the gnu gpl, for the free software release. Last week the mozilla foundation released version 2. After opting into the copyleft licence, the source code is readily available, and it allows others to modify and develop the code. Gnu general public license v3 gpl3 369497 code license managed by kevin. All about the common development and distribution license cddl. At ifross the licenses for free software, open source, open content, open data. 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. The opensource license usually known as mit license, a. When choosing a license, first, if at all possible, work with a lawyer to determine the open source license thats best for your project. Copyleft is a term coined by the fsf and implies that if you distribute a derivative work of a work under a copyleft license, you must distribute the derivative under the same license as the original work it may however be combined with works under a permissive license that is deemed compatible, read on. The gnu gpl allows users to change and share all versions of a program.
But, what does the classpath exception from gnus implementation have to with oracles jdk. And if you make modifications to the code under mspl, those modifications must also follow that license. A copyleft license permits embedding in a larger program only if the whole combined program is released under that license. Copyleft licensing is favourable for software coders. Copyleft is a name for a type of a license for free content or free software. 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. Famous gpl software projects like linux and mysql are considered to be the closest realization of the open philosophy free, growing, and communityimproved software, available to everyone. The gnu general public license gpl is the principal copyleft license. This solution is ingenious in the way that copyleft itself was an ingenious way to use to reverse the. This is a lax, permissive free software license, compatible with the gnu gpl, which. Various licenses and comments about them gnu project. Boston, ma wednesday, november 15, 2006 the free software foundation fsf welcomed the public commitment from sun microsystems to distribute its proprietary java platform under the gnu general public license gpl 1 the worlds most widely used free software license.
It has been approved by the free software foundation fsf as a free software license, and by the open source initiative osi as an open source license. A stronger copyleft license is the agpl which requires the publishing of the source code also for the usage case software as a service, see also the term sometimes used, service as a software substitute saass e. Libreoffice is being developed under two copyleft licences. Open source and copyleft licenses 178 words 1,188 characters rdisc this program was developed by sun microsystems, inc. When distributing the software, include this license header.
On selling exceptions to the gnu gpl free software. Richard stallman created the gpl to protect the gnu software from becoming proprietary, and it is a specific implementation of. Whats the difference between permissive and copyleft. Thus any software that uses any of the gpl open source components is to be released in full source code and all other rights.
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