Start studying bcis midterm 2 technology and action chapter 8. Examples of software commonly used under the gpl are the linux kernel and the rest of the gnulinux operating system, including the gcc compiler, git, filezilla and wordpress, just to name a few. Copyleft licenses are also known as reciprocal licenses or. Different types of software licenses require you to meet certain. Whitesource concluded that use of permissive opensource licenses continues to rise, while usage of copyleft licenses, and the gplfamily in particular, continues to decrease. The mpls filelevel copyleft is designed to encourage contributors to share modifications they make to your code, while still allowing them to.
Copyleft licenses are licenses that require redistributed copies and derivative works to be under the same license. The likeminded folks in redmond are prepared to aid you. Non copyleft licenses are considered as permissive licenses, mostly because they allow creating derivative works under other license terms. 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 30 31 32 e. A commercial software license is intended for business use and specifies the number of computers the software may be used by, whether it can be used on a lan configuration, etc. Advantages of copyleft focusing on the gpl license. This license is aimed at giving and protecting all users unlimited freedom to use, study, and privately modify the software, and if the user adheres to the terms and conditions of the gpl, freedom to redistribute. Copyleft licenses enforce the publication of the source code under the copyleft license. Oct 24, 2019 while the copyleft license used to be the most common open source license in use, over the past few years weve seen a decline in copyleft license use and a rise in permissive licenses. It enforces copyleft which means that anyone who distributes this code whether it has been modified or not must enforce the same rights on that work. This is in distinction to permissive free software licenses, of which the bsd licenses and the mit license are widely used examples. Linux essentials chapter 2 exam flashcards quizlet. The following licenses are sorted by the number of conditions, from most gnu agplv3 to none unlicense.
Gnu general public license v3 gpl3 368600 code license managed by kevin. Open source licenses grant permission for anybody to use, modify, and share licensed software for any purpose, subject to conditions preserving the provenance and openness of the software. All free software is open source software, but not all open source software is considered as free software. General public licenses are a popular copyleft license used in software. It gives everyone the ability to use, modify, distribute and run the software.
The gnu general public license is often called the gnu gpl for short. Because the operating system and associated development tools are free if she complies with the copyleft license what is an enduser license agreement eula. Copyleft is a kind of software license used by owners. Is there a generally accepted anticopyleft clause or license. When an open source license is not copyleft, that means software released under that license can be used as part of programs distributed under other licenses, including proprietary nonopensource licenses. Most copyleft licenses are open source, but not all open source licenses are copyleft. The concept of copyleft is central to many programming projects, and the license is most commonly used for software, digital art, writings, and. The concept of copyleft is central to many programming projects, and the license is most commonly used for software, digital art, writings, and other creative content. Copyleft is a specific license granted under law, and the international statutes governing law are the mechanisms that establish and protect copyleft. And what if i use gpl software, but dont modify it, can i distribute it with my application. Get the details on how this licensing works and what rights it conveys. Use the license preferred by the community youre contributing to or depending on.
You must make the source code for any of your changes available under mpl, but you can combine the mpl software with proprietary code, as long as you keep the mpl code in separate files. Materials passing through limewire may or may not be protected by their own s or other licenses. A tale of two copyleft licenses while determining the proper methodology and criteria to yield an accurate count remains difficult, the gpl is generally considered one of the most widely used free software licenses. This means freedom to use and develop your own technology, a huge benefit for users, society in terms of free knowledge, transparency and security. There are variations, of coursethe lgpl, for example, is a weak copyleft. 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. In the gnu project, the specific distribution terms that we use for most software are contained in the gnu general public license. This type of software license is perhaps the most popular license used with free and open. The licenses for most software and other practical works are designed to take away your freedom to share and change the works. The gnu gpl is the most widely used free software license and has a strong copyleft requirement. 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. Gpl was the first copyleft license for general use. In the past, software was often made available for free by simply submitting it into the public domain. As the gnu general public license is the most commonly used copyleft license, this is a requirement most developers will face at some point.
This provision allows limitations on the use of names of licensor for publicity purposes. It is a method for making a program, code, or another piece of work free. This license is aimed at giving and protecting all users unlimited freedom to use, study, and privately modify the software, and if the user adheres to the terms and conditions of the gpl, freedom to redistribute the software or any modifications to it. When distributing derived works, the source code of the work must be made available under the same license. The gnu free documentation license is another example of a copyleft non software license. Thethe biggest issue under these copyleft licenses is going to be that youre forced to release your own source code for your software, and youre forced to allow others to use it. A copyleft license allows users of the software to copy, make changes, and then distribute their adaptation. The gnu general public license is a free, copyleft license for software and other kinds of works.
Whats the difference between permissive and copyleft. It is important to make a difference between free software and open source software. The gnu general public license, originally written by richard stallman, was is first and most prominent software copyleft license. Copyleft is a general concept, and you cant use a general concept directly. Copyleft is a term used primarily when discussing licensing for open source code usage. As explained, using opensource code with a copyleft license attached means that downstream projects cannot add more restrictions to the use of the software. Strong copyleft licenses, among other things, require that the source code for the licensed software including any modifications be made available to the public, typically when the software is. The firefox browser uses a similar copyleft license. Copyleft license means any license that requires, as a condition of use, modification or distribution of any software or content, that such software or content, or other software or content incorporated into, derived from, used, or distributed with such software or content.
Copyleft is a type of license that attempts to ensure that the public retains the freedom to use, modify, extend and redistribute a creative work and all derivative works i. The concept of copyleft is designed to be the opposite of it allows software to be freely copied and shared. Both open source and copyleft allow for source code to be modified and distributed. Most of them are equivalent except for details of wording, but the license used for bsd until 1999 had a special problem. Open source licenses are licenses that comply with the open source definition in brief, they allow software to be freely used, modified, and shared. For example, the bsd license is a non copyleft open source license. Apr 16, 2020 by 2019, 33 percent of the software in the whitesource data set relied on copyleft licenses while 67 percent of the software favored a permissive opensource license. 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. Understanding mongodbs new copyleft open source license. Copyleft licensing is favourable for software coders. Some people use the pejorative name viral license for a copyleft license. Such licenses are usually called either non copyleft or permissive.
The internet provides a suitable platform for sharing and developing source code and open collaboration results in faster and more efficient development. Here you will find an archive of all the copyleft and open source licenses that have been published in the past. The gnu general public license gnu gpl or gpl is a series of widely used free software licenses that guarantee end users the freedom to run, study, share, and modify the software. Sep 06, 2019 it is similar to the share alike stipulation of the creative commons licenses and the sa icon resembles the copyleft icon. Mpl is a copyleft license that is easy to comply with.
Copyleft licenses list tldrlegal software licenses. A legal contract between the author of software and the end user that defines how the software can be used. Previously, the mongodb software was licensed under the gnu affero general public license v. 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. What is a special copyleft license used for software answers. Limewire itself was released under a gnu general public license, a copyleft style license used for free software distribution.
For example, if you write an application that does certain things, and you dont want other competitors to know how you make those things. A major difference between the set of permissive and copyleft free software licenses is that when the software is being redistributed either modified or unmodified, permissive licenses do not force the redistributor to open the modified source code. If a license is not copyleft, but it is foss, the user may depending on the exact terms of the license, be able to release binaryonly copies of the software, with limited distribution e. How to choose the best license for your open source. In legal terms, copyleft is an optional method to protect the four free software freedoms. Copyleft refers to licenses that allow derivative works but require them to use the same license as the original work. Top 10 gnu gpl license questions answered whitesource. There are many variants of simple noncopyleft free software licenses, such as the expat license, freebsd license, x10 license, the x11 license, and the two bsd berkeley software distribution licenses. The licenses were originally written by richard stallman, former head of the free software foundation fsf, for the gnu project, and grant the recipients of a. Copyleft is a form of licensing, and can be used to maintain conditions for works ranging from computer software, to documents, to ar. For software developers, business owners, and anyone else with an interest in exploring how software works, an understanding of the basics of open source and copyleft can be a helpful when determining which type of license to use to distribute your software. Copyleft provisions serve to preserve programs while allowing them to be distributed. This means the copyleft forces derivative, extended and even combined works, to be licensed under the terms of the original license. Frequently answered questions open source initiative.
The gpl is a copyleft license, which means that derivative work can only be distributed under the same license terms. The problem with this is that any person can then use the software and alter it, thus presenting a different program from what was originally intended. Gpl general public license this is the most widely used license but also one to be wary of. Then do i have to release my application under the gpl, or can i just supply the modified software under the gpls terms. In other words, the code is free to use, to share and modify but any resultant works must be distributed under the same license. The use of software licenses for nonsoftware work is generally discouraged. 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.
The most wellknown free software license that uses strong copyleft is the gnu general public license. Before someone can license software under a copyleft license, they must first own the to that software, thus giving them the right to distribute it. A weak copyleft license, such as the gnu lesser gpl, applies only. Bsd license problem gnu project free software foundation. The lesser general public license is sometimes described as a weak copyleft license, because code licensed under lgpls terms can be combined with code under nonfree licenses, and is sometimes used in that fashion. How to choose the best license for your open source software project getting the right license for your open source project can mean the difference between success and failure for your software. Copyleft is a form of licensing, and can be used to maintain conditions for works ranging from computer software, to.
This provision also yields additional compatibility with non copyleft free software licenses that prohibit the use of the licensors name on unmodified versions or other prohibitions on advertising rights. That is to say, although it is possible to use limewire to infringe. Almost all corporate environments make use of gpl licensed software. For most of its history for 16 years from june 1991 to june 2007 there was really only one version of the gpl, version 2. If a company were to develop a program using open source components with copyleft licenses and distributed that program, anyone would have the. What is a popular copyleft license used for software. Businesses use copyleft licenses to protect their software and different benefits within them from other companies essentially making the same type of software. Copyleft licenses ensure all future derivatives of the product to include the original copyleft word for word, thus keeping the product free whenever it changes. That said, the copyleft gplv3 license is still the third most popular open source license out there, and overall, copyleft licenses account for nearly 40% of. In fact, copyleft is grounded in the concept of, without which copyleft couldnt exist. It lets people do almost anything they want with your project, like making and distributing. Proprietary software contain open source copyleft code. Copyleft software licenses are considered protective or reciprocal, as contrasted with permissive freesoftware licenses.
How to choose the best license for your open source software. Users are permitted to engage in copying and distributing ed materials. When an open source software project is published with a copyleft license, other developers have the right to use, modify, and share the work as long as the reciprocity obligation is maintained. The largest difference between the gplv2 and bsd licenses is. Copyleft license legal definition of copyleft license by. Copyleft is free software license requiring authors to permit some of their work to be reproduced. Copyleft is the idea and the specific stipulation when distributing software that the user will be able to copy it freely, examine and modify the source code, and redistribute the software to others free or priced as long as the redistributed software is also passed along with the copyleft stipulation.
An alternate form of copyleft, the gnu affero general public license agpl is designed for programs that are likely to be used on servers. By 2019, 33 percent of the software in the whitesource data set relied on copyleft licenses while 67 percent of the software favored a permissive opensource license. The gnu free documentation license is another example of a copyleft nonsoftware license. The first form of copyleft licensing is called the gnu general public license gpl. An example of a copyleft free software license is the often used gnu general public license gpl, also the first copyleft license. Copyleft, distinguished from, 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. 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. Free software licenses can be divided into two broad categories. There are multiple variants of the gnu gpl, each with different requirements. The following licenses are sorted by the number of conditions, from most gnu agplv3 to. Why dash uses the mit license and not a copyleft gpl. The use of software licenses for non software work is generally discouraged. It considers free software permissive license group to be a reference implementation of a free software license. My case in point is, i have a php framework which i use the geshi library to highlight some output.
A strong copyleft license, such as the gnu gpl license, applies to all derived works and software components in the package. In other words, whereas the gpls opponent in employing copyleft is nonfree licensing terms, your opponent in employing copyleft will be copyleft terms except for your own copyleft terms. Creative commons, copyleft, and other licenses copyright. It ensures that modified versions used to implement services available to the public are released as source code to the public. 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. Bcis midterm 2 technology and action chapter 8 quizlet. Why dash uses the mit license and not a copyleft gpl license. 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. Osi agrees with fsf on all widely used free software licenses, but differ from fsfs list, as it approves against the open source definition rather than the free software definition. Learn vocabulary, terms, and more with flashcards, games, and other study tools. With law, authors have complete control over their materials. If you have a dependency that doesnt have a license, ask its maintainers to add a license.