Linked from

The 13 pages that link to Copyleft, each with the reason it gives.

• Open-source softwareRelated: Some open-source licenses impose reciprocal sharing obligations; others permit proprietary derivatives.

• Richard StallmanBroader topic: Stallman developed copyleft as a legal strategy for protecting software freedom.

• Creative CommonsCompared with: Share-alike resembles copyleft, but Creative Commons licenses cover many kinds of works beyond software.

• GNU General Public LicenseNarrower topic: The GPL is the best-known implementation of copyleft for software.

• GNU ProjectRelated: Copyleft lets GNU software be shared while resisting efforts to turn modified versions proprietary.

• Copyright lawRelated: It uses copyright control to sustain shared access rather than exclusivity alone.

• Free softwareBroader topic: It uses copyright conditions to keep redistributed versions free.

• Free Software FoundationRelated: The FSF developed copyleft as a way to keep software freedoms intact across redistribution.

• Free software movementRelated: Copyleft uses copyright law to keep software and its derivatives free.

• Free-culture movementRelated: It protects downstream sharing within the movement’s licensing toolkit.

• Open sourceRelated: It explains the mechanism behind licenses that keep modified versions open.

• Criticism of copyrightCompared with: It retains copyright’s legal framework while redirecting exclusive rights toward shared reuse.

• Open knowledgeRelated: Its share-alike requirement is one way to keep derivative knowledge openly reusable.