Glossary/Copyleft

Glossary | Concepts | Copyleft

'House' Definition

Copyleft is a licensing method that allows users to freely use, modify, and distribute a work, as long as any derivative works are also shared under the same license. A key feature of copyleft is that adaptations must remain freely available, ensuring the work and its derivatives cannot be made proprietary. This promotes collaboration and the open exchange of ideas.

History

The concept of copyleft originated in the 1980s with Richard Stallman, who developed the GNU General Public License (GPL) as part of the Free Software Foundation's GNU Project. Stallman created the GPL to ensure that software remains free as in freedom, granting users the liberty to run, study, modify, and share software. This countered the rise of proprietary software by requiring modified versions to use the same license. The GPL became the foundation for open-source projects like the Linux kernel and later influenced creative works through licenses such as Creative Commons ShareAlike.

Examples

• The GNU General Public License
• Creative Commons ShareAlike License