Type: CopyLeft

Enumeration of CopyLeft license families that indicates the level of freedom to modify, copy, share, and redistribute the software, and how derivative works must be licensed, and how source code must be made available. For more information, see https://en.wikipedia.org/wiki/Copyleft


  • MAXIMAL: Maximal copyleft licenses answer the question “When does the license require you to share?” differently than other families. Maximal copyleft licenses require you to share software you make with others, and to license that software alike when you do.

Free-software licenses that are "maximal" copyleft include Cryptographic Autonomy License.

For more information, see https://blueoakcouncil.org/copyleft#maximal-copyleft-family

  • NETWORK: A variation of STRONG. In addition to the requirements of strong copyleft licenses, network copyleft licenses require you to share larger programs that you build with the licensed software not just when you give copies to others, but also when you run the software for others to use over the Internet or another network.

Free-software licenses that are "network" copyleft include the Affero General Public License (GNU AGPL)

For more information, see https://blueoakcouncil.org/copyleft#network-copyleft-family

  • STRONG: The most restrictive license type. This license type requires that any derivative works be licensed under the same license as the original work.

The GNU General Public License is an example of a license implementing strong copyleft. A stronger copyleft license is the AGPL, which requires the publishing of the source code for software as a service use cases.

For more information, see https://blueoakcouncil.org/copyleft#strong-copyleft-family

  • WEAK: This allows other software to link to the library and be redistributed without the requirement for the linking software to also be licensed under the same terms. Only changes to the software licensed under a "weak copyleft" license become subject itself to copyleft provisions of such a license. This allows programs of any license to be compiled and linked against copylefted libraries such as glibc and then redistributed without any re-licensing required.

Free-software licenses that are "weak" copyleft include the GNU Lesser General Public License and the Mozilla Public License.

For more information, see https://blueoakcouncil.org/copyleft#weak-copyleft-family

This page was generated: 2024-05-17