It's quite simple. All versions that are not coming from Thunderdark are derivative versions of the mod. That's true for Cal's UE version of MFFS and for our classic version of the mod. Now I'd prefer to stop discussing this topic and focus on the next steps in bringing you a stable release of MFFS classic.
This is not true. My version, (if you even call it a version since it is independent) is not a derivative and is independent from the GPL license legally. It does not use any code or textures from the old MFFS and was coded from the ground up. It's a completely different mod, both in code and in terms of theme and style. The only thing similar are the ideas of the mod. Ideas cannot be called "derivative". I had a lawyer look through my code in comparison to the original as well as the development and this is pretty much confirmed. Debate if you want, but this is a fact. Anyway, this is the end of discussion.