GPLv3 (General Public License version 3) is the most widely used open-source license, with strong requirements for copyright freedom. It grants and guarantees extensive rights to developers of open-source projects. Essentially, it allows users to legally copy, distribute, and modify the software, but the distribution of derivative code must be open-source and comply with the GPL. There are many variations of this license, each with slightly different requirements.
Requirements:
- Modified source code must also be made public.
- Copyright and license must be consistent with this license.
- After modification, explanations should be provided in the corresponding files.