The GNU General Public License (GPL) is a software license that gives users the freedom to modify and redistribute software. The GPL is often used for open source software, which is software that can be freely accessed, used, and modified by anyone. The GPL allows users to make changes to the software and redistribute it as they see fit.
The GPL is a copyleft license, which means that any derivative works must be licensed under the same or a compatible license. This ensures that everyone who has a copy of the software can make changes to it and redistribute it. The GPL is also a viral license, which means that any software that is based on GPL-licensed software must also be licensed under the GPL.
The GPL was created by the Free Software Foundation (FSF), a nonprofit organization that promotes free software. The FSF believes that all software should be free, and the GPL is one way to make that happen.
There are two main versions of the GPL: GPLv2 and GPLv3. GPLv2 is the most widely used version of the license, but GPLv3 is also popular. Many software projects release their software under both licenses, so that users can choose which one they want to use.