the.com/gpl
The license that makes you share your improvements, forever, with everyone.
means The GNU General Public License is a legal framework that lets anyone use, modify, and distribute software freely—but requires them to release improvements under the same terms, creating an obligation to give back.
from Born in 1989 when Richard Stallman needed a tool to protect the freedom of GNU's software from being locked up by corporations. It weaponized copyright law against itself: instead of restricting, it enforces sharing.
Viral inheritanceAny software that links GPL code must be GPL too
Linux's legal spineThe kernel, servers, Android—powered by GPL's share-alike requirement
Business frictionCompanies love open source until GPL forces code release
Three versions existv2, v3, and the rarely-used Affero variant