GPL stands for General Public License and is a legal method of allowing open source software, developed by independent developers, to be used and modified by others.GPL code is therefore free software, because users are free to use it and modify it in any way they see fit. Through modifying the source code of software, developers have the ability not only to create entirely new pieces of software, but also influence the direction of the original projects themselves.
The GNU General Public License (GPL) is one of several free software license programs available. A few of the more popular are the MIT license, which is used by the X Window System, and the BSD license, used by Apple’s Mac OS X.
What is copyleft?
Copyright is a law that restricts the right to use, modify, and share creative works without the permission of the copyright holder. When an author releases a program under a copyleft license, he makes a claim on the copyright of the work and issues a statement that other people have the right to use, modify, and share the work as long as the reciprocity obligation is maintained.
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 GNU General Public License is a free, copyleft license for software and other kinds of works.
The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program–to make sure it remains free software for all its users. We, the Free Software Foundation, use the GNU General Public License for most of our software; it applies also to any other work released this way by its authors. You can apply it to your programs, too.
When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for them if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things.
To protect your rights, we need to prevent others from denying you these rights or asking you to surrender the rights. Therefore, you have certain responsibilities if you distribute copies of the software, or if you modify it: responsibilities to respect the freedom of others.
For example, if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same freedoms that you received. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.
Developers that use the GNU GPL protect your rights with two steps: (1) assert copyright on the software, and (2) offer you this License giving you legal permission to copy, distribute and/or modify it.
For the developers’ and authors’ protection, the GPL clearly explains that there is no warranty for this free software. For both users’ and authors’ sake, the GPL requires that modified versions be marked as changed, so that their problems will not be attributed erroneously to authors of previous versions.
Some devices are designed to deny users access to install or run modified versions of the software inside them, although the manufacturer can do so. This is fundamentally incompatible with the aim of protecting users’ freedom to change the software. The systematic pattern of such abuse occurs in the area of products for individuals to use, which is precisely where it is most unacceptable. Therefore, we have designed this version of the GPL to prohibit the practice for those products. If such problems arise substantially in other domains, we stand ready to extend this provision to those domains in future versions of the GPL, as needed to protect the freedom of users.
Finally, every program is threatened constantly by software patents. States should not allow patents to restrict development and use of software on general-purpose computers, but in those that do, we wish to avoid the special danger that patents applied to a free program could make it effectively proprietary. To prevent this, the GPL assures that patents cannot be used to render the program non-free.
Techopedia Explains GNU General Public License (GPL)
In 1989, Richard Stallman produced the first GPL through the GNU Program. The GNU Program was launched in 1984 for the express purpose of developing operating systems that are similar to Unix, except that they are open source. Under the GPL provisions, owners may sell copies of programs under GPL, or distribute them for free. To do so, licensees must adhere to the designated terms and conditions of the GPLs. Under a GPL, owners are permitted to modify digital materials as well. The GPL is widely used and the most popular free license of its kind.
What are the GPL license terms and conditions?
If you have used a GPL component in your software, then your entire software is considered a ‘work based on’ a GPL and, therefore:
- You are not allowed to claim patents or copyright on the software. Moreover, you are obligated to display a copyright notice, disclaimer of warranty, intact GPL notices, and a copy of the GPL.
- You are not allowed to change the license or introduce additional terms and conditions.
- You are under the reciprocity obligation, which means you are obligated to release the source code and all of the rights to modify and distribute the entire code.
Can you sConclusionell GPL software/code?
Yes, the GPL license allows users to sell the original as well as the modified software. It may be confusing, but free software is referred to as free in terms of freedom and not in terms of price. As Richard Stallman explains it, free software means free as in “free speech,” not free as in “free beer.”
However, if someone buys your program for a fee, GPL gives him/her the liberty to release it to the public, with or without a fee.
The GPL is short for General Public License. The GPL is an agreement that makes it possible for software and other digital files to be copied, distributed, modified and re-distributed by anyone