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Proprietary software


The Design Science License is a strong copyleft license that can apply to any work—not only software or documentation, but also to literature, artworks, music, photography, and video. It was created by Michael Stutz after his interest in applying GNU-style copyleft to non-software works, which later came to be called Open content. In the 1990s the DSL was used on music recordings, visual art, and even novels. It is now hosted on the Free Software Foundation website’s license list, but it is not considered compatible with the GPL by the Free Software Foundation. Free-software licenses that use “weak” copyleft include the GNU Lesser General Public License and the Mozilla Public License.

Can I include GPL code in my project?

You may copy, distribute and modify the software as long as you track changes/dates of in source files and keep modifications under GPL. You can distribute your application using a GPL library commercially, but you must also provide the source code. GPL v3 tries to close some loopholes in GPL v2.

Until the late 1960s computers—large and expensive mainframe computers, machines in specially air-conditioned computer rooms—were leased to customers rather than sold. Service and all software available were usually supplied by manufacturers without separate charge until 1969. Computer vendors usually provided the source code for installed software to customers.[citation needed] Customers who developed software often made it available to others without charge. Closed source means computer programs whose source code is not published. It is available to be edited only by the organization that developed it.

The term “the Program” means one particular work that is licensed under GPLv3 and is received by a particular licensee from an upstream licensor or distributor. The Program is the particular work of software that you received in a given instance of GPLv3 licensing, as you received it. Any material that can be copyrighted can be licensed under the GPL. GPLv3 can also be used to license materials covered by other copyright-like laws, such as semiconductor masks. So, as an example, you can release a drawing of a physical object or circuit under the GPL.


In 2011 it was noticed that GNU Emacs had been accidentally releasing some binaries without corresponding source code for two years, in opposition to the intended spirit of the GPL, resulting in a copyright violation. Richard Stallman described this incident as a “very bad mistake,” which was promptly fixed. The FSF did not sue any downstream redistributors who also unknowingly moto btc gard violated the GPL by distributing these binaries. The Free Software Foundation (which holds the copyright of several notable GPL-licensed software products and of the license text itself) asserts that an executable which uses a dynamically linked library is indeed a derivative work. This does not however apply to separate programs communicating with one another.

Examples of non-copyleft (“permissive”) free-software licenses include the X11 license, Apache license and the BSD licenses. The concrete effect of strong vs. weak copyleft has yet to be tested in court. Copyleft licenses necessarily make creative use of relevant rules and laws. For example, when using copyright law, those who contribute to a work under copyleft usually must gain, defer or assign copyright holder status.

Popular copyleft licenses, such as the GPL, have a clause allowing components to interact with non-copyleft components as long as the communication is abstract, such as executing a command-line tool with a set of switches or interacting with a Web server. 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 normally.

The public consultation process was coordinated by the Free Software Foundation with assistance from Software Freedom Law Center, Free Software Foundation Europe, and other free software groups. Comments were collected from the public via the web portal, using purpose-written software called stet. The version numbers diverged in 1999 when version 2.1 of the LGPL was released, gplonline which renamed it the GNU Lesser General Public License to reflect its place in the philosophy. The second version of the license, version 2, was released in 1991. Over the following 15 years, members of the free software community became concerned over problems in the GPLv2 license that could let someone exploit GPL-licensed software in ways contrary to the license’s intent.

If the GPL is used for computer fonts, any documents or images made with such fonts might also have to be distributed under the terms of the GPL. A number of businesses use multi-licensing to distribute a GPL version and sell a proprietary license to companies wishing to combine the package with proprietary code, using dynamic linking or not.

LGPLv3 and GPLv2-only can thus commonly not be linked, as the combined Code work would add additional LGPLv3 requirements on top of the GPLv2-only licensed software. Code licensed under LGPLv2.x without the “any later version” statement can be relicensed if the whole combined work is licensed to GPLv2 or GPLv3. If a user wants to combine code licensed under different versions of GPL, then this is only allowed if the code with the earlier GPL version includes an “or any later version” statement. For instance, the GPLv3 licensed GNU LibreDWG library can’t be used anymore by LibreCAD and FreeCAD who have GPLv2 only dependencies.

Some features, such as support for some external libraries (libx264 and libx265 for example) and various filters, are covered by the GNU General Public License (GPL) version 2 or later (see commercial x264 license exception below). See in the source to see a list of GPL parts of FFmpeg and which external libraries require GPL. There are certain circumstances, such as with U.S. government works as described above, where it is not easy to apply a license, and the software must be released into the public domain.


Compare this to a situation where the web site contains or links to separate GPLed programs that are distributed to the user when they visit the web site (often written in JavaScript, but other languages are used as well). In this situation the source code for the programs being distributed must be released to the user under the terms of the GPL. Part of the wexcoin idea of free software is that users should have access to the source code for the programs they use. Those using your version should have access to the source code for your version. The whole point of the GPL is that all modified versions must be free software—which means, in particular, that the source code of the modified version is available to the users.

What is Linux?

“Comparative merits of GPL, BSD and Artistic licences (Critique of Viral Nature of GPL v.2 – or In Defense of Dual Licensing Idea)”. Both LibreCAD and FreeCAD both want to use LibreDWG and have patches available for supporting the DWG file format library, but can’t integrate them. The programs have dependencies on the popular GPLv2 license while the Free Software Foundation will only let LibreDWG be licensed for GPLv3 use, not GPLv2. “A Quick Guide to GPLv3 – GNU Project – Free Software Foundation (FSF)”.

Strong and weak copyleft

The licensee is allowed to charge a fee for this service, or do this free of charge. This latter point distinguishes the GPL from software licenses that prohibit commercial gplonline redistribution. The FSF argues that free software should not place restrictions on commercial use, and the GPL explicitly states that GPL works may be sold at any price.

How does Linux differ from other operating systems?

In fact, as we argued in previous posts, open source software may sometimes be safer than proprietary software since you have more people checking and fixing problems. This means that any software that is written based on any GPL component must be released as open source. The result is that any software that uses any GPL open source component (regardless of its percentage in the entire code) is required to release its full source code and all of the rights to modify and distribute the entire code.

The FSF opposes the application of US export control laws to free software. Therefore, no country’s government is actually deprived of free software by US export control laws, while no country’s citizens should be deprived of free software, regardless of their governments’ policies, as far as we are concerned. Copies of all GPL-licensed software published by the FSF can be obtained from us without making any representation about where you live or what you intend to do. At the same time, the FSF understands the desire of commercial distributors located in the US to comply with US laws.

  • This means you can avoid the risk of having to compete with a proprietary modified version of your own work.
  • However, any developer who modifies an LGPL-covered component is required to make their modified version available under the same LGPL license.
  • It’s more future-proof because it no longer includes the FSF’s postal mailing address.
  • Some laws used for copyleft licenses vary from one country to another, and may also be granted in terms that vary from country to country.
  • GPL is the acronym for GNU’s General Public License, and it’s one of the most popular open source licenses.
  • Thus we recommend that you always apply an approved Open Source license to software you are releasing, rather than try to waive copyright altogether.

Examples of such companies include MySQL AB, Digia PLC (Qt framework, before 2011 from Nokia), Red Hat (Cygwin), and Riverbank Computing (PyQt). Other companies, like the Mozilla Foundation (products include Mozilla Application Suite, Mozilla Thunderbird, and Mozilla Firefox), used multi-licensing to distribute versions under the GPL and some other open-source licenses. Code licensed under LGPL is permitted to be linked with any other code no matter what license that code has, though the LGPL does add additional requirements for the combined work.

In the case of proprietary software with source code available, the vendor may also prohibit customers from distributing their modifications to the source code. The owner of proprietary software exercises certain exclusive rights over the software. The owner can restrict use, inspection of source code, modification of source code, and redistribution. In 1983, binary software became copyrightable in the United States as well by the Apple vs. Franklin law decision, before which only source code was copyrightable. Additionally, the growing availability of millions of computers based on the same microprocessor architecture created for the first time an unfragmented and big enough market for binary distributed software.

If we permitted company A to make a proprietary file, and company B to distribute GPL-covered software linked with that file, the effect would be to make a hole in the GPL big enough to drive a truck through. This would be carte blanche for withholding the source code for all sorts of modifications and extensions to GPL-covered software. Some programs copy parts of themselves into the output for technical reasons—for example, Bison copies a standard parser program into its output file.

The cell where they meet will tell you whether or not this combination is permitted. The GNU Affero GPLrequires that modified versions of the software offer all users interacting with it over a computer network an opportunity to receive the source. What the company is doing falls under that meaning, so the company must release the modified source code.

Can I use GPL software for commercial purposes?

My software, Teem, is released under the GNU Lesser General Public License (“LGPL”), for a variety of reasons. It is important to understand the difference between the LGPL and the GNU General Public License (“GPL”). Some people dismiss all GNU licenses as “viral”, which is both unfortunate and false.

Some devices utilize free software that can be upgraded, but are designed so that users are not allowed to modify that software. There are lots of different ways to do this; for example, sometimes the hardware checksums the software that is installed, and shuts down if it doesn’t match an expected signature. The manufacturers comply with GPLv2 by giving you the source code, but you still don’t have the freedom to modify the software you’re using.

In such cases, the copied text in the output is covered by the same license that covers it in the source code. Meanwhile, the part of the output which is derived from the program’s input inherits the copyright status of the input. Both versions of the GPL have an exception to their copyleft, commonly called the system library exception.

Is Linux a proprietary software?

They can’t, for example, withdraw money from your account using only the account number. However, with a little more obtainable information, such as your address or driver’s license number, someone with your account number may have the ability to manipulate and compromise your account.

The Lesser General Public License (LGPL) is a more permissive license (weak copyleft). LGPL is used to license free software so that it can be incorporated into both free andproprietarysoftware. GPL requires you to release the modified source code only if you release the modified program. If you’ve modified a program’s source code for personal use, there’s no need to release its source code. However, if you make the modified program available to the public, you will have to make the code public too.

As of 2015[update], MIT was the most popular software license on GitHub, ahead of any GPL variant and other free and open-source software (FOSS) licenses. Notable projects that use the MIT License include the X Window System, Ruby on Rails, and Node.js. As a permissive license, it puts only very limited restriction on reuse and has, therefore, high license compatibility.

This allowed communication may or may not include reusing libraries or routines via dynamic linking– some commentators say it does, the FSF asserts it does not and explicitly adds an exception allowing it in the license for the GNU Classpath re-implementation of the Java library. This ambiguity is an important difference between the GPL and the LGPL, in that the LGPL specifically allows linking or compiling with the covered work.

Types and relation to other licenses

They have a right to choose to whom they distribute particular copies of free software; exercise of that right does not violate the GPL unless they add contractual restrictions beyond those permitted by the GPL. However, if you link nonfree libraries with the source code, that would be an issue you need to deal with. It does not preclude releasing the source code under the GPL, but if the libraries don’t fit under the “system library” exception, you should affix an explicit notice giving permission to link your program with them. The FAQ entry about using GPL-incompatible libraries provides more information about how to do that. A major goal of the GPL is to build up the Free World by making sure that improvement to a free program are themselves free.

By submitting the copyright of their contributions under a copyleft license, they deliberately give up some of the rights that normally follow from copyright, including the right to be the unique distributor of copies of the work. Traditional copyright law is designed to promote progress by providing economic benefits to creators. When choosing to copyleft their work, content creators may seek complementary benefits like recognition from their peers. The open-source culture had been described as a gift culture, where social status is determined by an individual’s contributions. Working on free software may also be an outlet for programmers to fill a need they have noticed.

Who “owns” Linux?

For some creators, keeping their work open is an incentive in and of itself. For these programmers, preventing commercial enterprises from absorbing and selling their product is another incentive.

Distributing and Using Open Source Software

Frequently Asked Questions about the GNU Licenses – GNU Project – Free Software Foundation. The license was originally called the GNU Library General Public License and was first published in 1991, and adopted the version number 2 for parity with GPL version 2. The LGPL was revised in minor ways in the 2.1 point release, published in 1999, when it was renamed the GNU Lesser General Public License to reflect the FSF’s position that not all libraries should use it. Version 3 of the LGPL was published in 2007 as a list of additional permissions applied to GPL version 3.

Can I modify GPL code?

Proprietary software, also known as closed-source software, is non-free computer software for which the software’s publisher or another person retains intellectual property rights—usually copyright of the source code, but sometimes patent rights.

If you receive software under an Open Source license, you can always use that software for commercial purposes, but that doesn’t always mean you can place further restrictions on people who receive the software from you. In particular, copyleft-style Open Source licenses require that, in at least some cases, when you distribute the software, you must do so under the same license you received it under. You are allowed to sell open source software for any amount you like. You are allowed to charge reasonable cost for supplying the source code. And of course modified open source software may only distributed with an open source license.


There has been debate on whether it is a violation of the GPL to release the source code in obfuscated form, such as in cases in which the author is less willing to make the source code available. The consensus was that while unethical, it was not considered a violation. The issue was clarified when the license was altered with v2 to require that the “preferred” gplonline version of the source code be made available. The terms and conditions of the GPL must be made available to anybody receiving a copy of the work that has a GPL applied to it (“the licensee”). Any licensee who adheres to the terms and conditions is given permission to modify the work, as well as to copy and redistribute the work or any derivative version.