Copyleft Licensing
Copyleft is a legal and licensing concept that uses copyright law to ensure that derivative works of a free or open-source software (FOSS) project remain freely available under the same terms. It requires that any modified or extended versions of the software, when distributed, must be licensed under the same copyleft license, thus preserving user freedoms. This contrasts with permissive licenses that allow proprietary reuse.
Developers should learn about copyleft licensing when working on or contributing to open-source projects to ensure compliance and understand the implications for software distribution. It is crucial for projects aiming to enforce software freedom, such as the GNU General Public License (GPL) used in Linux, to prevent proprietary forks. Use cases include developing community-driven software, ensuring long-term accessibility, and avoiding legal risks in commercial integrations.