The full form of GPL is a general public license, and right now, it is one of the most popular and widely used open-source licenses. Richard Stallman created GPL because he wanted to protect the new software from being made proprietary. And this is where his copyleft concept came into play.
Naturally, many questions might come to your mind regarding what GPL is and others related to it. So in this article, we will discuss 10 of the most common GPL license questions and their answers.
1. What is the copyleft concept?
Answer- copyleft is the concept where no one can use, modify, and share creative work without the permission of the copyright holder. When an author releases a program or software with a copyleft license, it is like claiming the copyright of the work and making it clear that other people can use, modify, and share that work. Still, the reciprocity obligation has to be maintained.
According to the copyleft concept, the rights of the users and their convenience is given more preference over the commercial requirements of the software makers. Copyleft is also developed to support the users to make improvements to the already existing software.
2. What are the terms and conditions of the GPL license?
Answer- If you are using any component related to GPL in your software, that means you have agreed to the terms and conditions of GPL. Hence it is essential to know what they exactly are.
Firstly you can not make any claims on the patent for copyright on the software. You are also obligated to display a copyright notice, disclaimer of warranty, intact GPL notices, and a copy of the GPL.
Secondly, you cannot change the license or introduce any additional terms and conditions.
Thirdly, you are obligated to release the source code and all the rights to modify and distribute the entire code. This term is called reciprocity obligation.
3. Is GPL enforceable?
Answer- GPL is a copyright license, and hence it is enforceable. The copyright holder of the GPL software can choose to enforce the GPL on the software’s distributed or derivative works.
For example, the FSF has the copyright of any component of the GNU system, like the GNU compiler collection. Since it is the copyright holder, it can enforce the copyleft requirements of the GNU general public license is copyright infringement occurs on that particular software.
4. Is it possible to sell GPL software or code?
Answer- in simple one word answer, yes. Does the GPL license allows the users to sell the original software and dumb modified one as well? It might be slightly confusing, but free software means it is free in terms of freedom but not in terms of price.
The GNU project encourages the people to redistribute and modify the software as much as they can and charge for it as much as they want. But all of this applies only to the part of the software which is executable. The source code can’t be modified or changed according to your wish.
So if you wish to sell a binary copy of the GPL software program, it is mandatory to include the complete source code or a formal written offer with a validity of a minimum of 3 years. So, if someone buys your program for a price, GPL allows them the freedom to release it to the public with or without a fee.
5. Is it safe to use GPL?
Answer- the GPL doesn’t have anything to do with the security of the code. It is a license which is concerned with the usage and distribution. So as far as the question about the safety of the GPL themes is concerned, we do not have to worry about it at all. The safety of a particular theme usually depends on how the theme was coded and whether correct and ethical coding practices were used. The GPL license does not have anything to do with it.
Usually, the pirated themes and the nulled themes are the ones that are kind of not secure and might contain Malware that can attack your device. Open-source software is safer than proprietary software because more people keep modifying the software and fixing the current issues.
6. Does the GPL license require the author to release the modified source code?
Answer- If you are using GPL and you are the author, you can release the modified source code only if you released the modified program. However, if you have modified a program’s source code so that you can use it personally, there is no need to release the source code. Another important point is that the source code will have to be made public if you release the modified program to the public.
7. What is the difference between GPLv2 and GPLv3?
Answer- Both GPLv2 and GPLv3 are different versions of GNU public licenses. The GPL can be considered as a template for all the succeeding versions. GPLv2 was introduced before GPLv3, and hence this makes the latter the latest version. The FSF tried to add more clarity to GPLv3 as to when the reciprocity obligation is triggered.
Additionally, it has also been seen that GPLv3 is made it more compatible with the other licenses. To combine two codes into a larger work, both the programs must permit it. If such rights are granted by both the licenses of the programs, they are compatible. By making the GPLv3 more compatible, the FSF expanded development options.
The difference between the two versions is that the GPLv3 was written to increase its users worldwide. The language used for GPL V2 was very US-centric. Hence the language in GPLv3 that was used to describe the license rights has been modified in such a way that the international laws will interpret it as the FSF intended it to be. Developers also get the opportunity to add local 10 km in GPLv3, which will further increase its usage outside the United States.
8. Can GPL license be mixed with other licenses?
Answer- usually, it is believed that the code covered by the GPL license cannot be mixed with code powered by other open source software licenses. Restrictions do indeed exist, but it is also possible under both GPLv2 and GPLv3. This information has been established even more clearly after a new language has been used in GPL V3.
The FSF has explicitly stated that GPLv3 is compatible with the Apache 2.0 license. However, there is an issue with the original BSD license as it imposes a specific requirement that is not in the GPL.
9. What does LGPL cover?
Answer- The lesser general public license is more permissive and can be considered a weak copyleft. LGPL is used to license free software so that it can be incorporated INR to both free and proprietary software.
There is one major difference between LGPL and GPL license- with LGPL, you do not have to open up the source code to your extensions to the software. You are only obliged to subject your modifications to the original free library to the LGPL. The free library is always subject to the LGPL. Any user of your software can modify, decompile, or replace the free LGPL library and use its modified version with your software.
It is also mandatory for you to permit reverse engineering of the work that uses the library to enable debugging when the LGPL library is modified replaced with later versions.
Additionally, LGPL is compatible with GPL. So if you want, you can upgrade to GPL and incorporate it entirely GPL licensed project. But the reverse process is not allowed, and you cannot re-license the GPL license code as LGPL.
10. What does AGPL cover?
Answer- AGPL stands for Affero general public license, which is a variation of the GPL and caters to programs that run on a server. If you are a developer and modify a program under the GPL, you have to release the modified program under the same license. However, if this program runs on a server only, you will not be expected to release it to the rest of the world.
The AGPL covers this case. Under the AGPL, the developer has to release the modified version of the program to everyone who uses the service.
So these were the top 10 questions about the GPL license answered. We chose the ones which were most commonly asked. GPL license is a topic regarding which you might have any doubts. So if you have any more questions on this topic, feel free to write to us, and we will try to answer it to the best of our ability.
Also, many of the questions might require legal advice, and the author of this blog is not a lawyer. Information provided is based on research, and if you want legal consultation, we suggest you contact your legal advisor.