REMINDER License plugins, forks, skins
Article 1 - DEFINITIONS
Module: means a set of sources files including their documentation that enables supplementary functions or services in addition to those offered by the Software.
External Module: means any or all Modules, not derived from the Software, so that this Module and the Software run in separate address spaces, with one calling the other when they are run.
Internal Module: means any or all Module, connected to the Software so that they both execute in the same address space.
These three definitions are quotes from contract CeCILL.
Plugins, forks, skins Guppy 5 are internal modules which the CeCILL License applies to it, and they must comply with the provisions of the License Agreement in their entirety.
This results in the requirement to include header files with CeCILL Copyright (C) ...
One exception is allowed for the author who submits his work to any license, in this case, is the copyright and intellectual property that applies
To read the license agreement in its entirety, please visit this link.