Copyleft Open Source License definition
Copyleft Open Source License means an Open Source License that requires, as a condition of distribution of the software, project, database or other work licensed thereunder, that other software, projects, databases or other work incorporated into, derived from or distributed with, such software, project, database or work (i) be disclosed or distributed in source code form, (ii) be licensed for purposes of preparing derivative works or (iii) be redistributed at no charge. Copyleft open-source software includes the GNU General Public License, the GNU Lesser General Public License, the GNU Affero General Public License, the Creative Commons Attribution Share-Alike License (CC BY-SA); and the Mozilla Public License.