Non-Permissive Open Source License definition
Non-Permissive Open Source License means an Open Source License that requires, as a condition of use, modification, or distribution of the open source software subject to the Open Source License, that the API be:
a) disclosed or distributed in source code form;
b) licensed for the purpose of making derivative works; or
c) re-distributable at no charge. These licenses are sometimes referred to as “copyleft” or “viral.” The most common examples of Non-Permissive Open Source Licenses are the GNU General Public License (GPL) and the Affero General Public License (AGPL).