Weak copyleft
Weak copyleft licenses are file-scoped reciprocal licenses. These licenses, like Mozilla Public License, set the reciprocity to the individual files within the project, not the whole project. File change or reuse must be licensed the same way as the original file, but there are no requirements placed on other files combined in new projects.
Strong copyleft
Strong copyleft licenses are project-scoped reciprocal licenses. These licenses, like GPL family of licenses and EUPL, set the reciprocity to include any code needed to create the resulting project. The derivative and/or combined work has to be licensed under the same license as the original work.
Knowledge ecosystem
Knowledge ecosystem aims for knowledge exploration, usually by research institutes, innovators, and technology entrepreneurs.
