Copyleft
lastmod 2014-05-03created 2014-05-031 edits
Copyleft is a concept opposed to copyright in its exclusive sense; rather than restricting use on the basis of copyright, it is a measure for sharing information on the basis of copyright. Advocates of copyleft usually argue that knowledge and information should not be monopolized by a few, but should be open to everyone. The main requirements of copyleft are that the right to use the information is passed on to the authors of derivative works, and that the passing on of these rights is not blocked.