Category:Copyleft

This category is for articles about licenses which:
 * 1) Contrary to the usual application of copyright law, aim to enable each recipient to help himself and to cooperate with others, and
 * 2) Require that modified versions be distributed wholly under the same licence ("share and share alike")

Note: this category differs substantially from Category:free software licenses in that it is not limited to software, and not all free software licenses are copyleft (some are permissive, like those of BSD and MIT).