ToME: the Tales of Maj'Eyal

I still dont really understand.I need a simple answer for that question:
Is any code(im not asking for any art-work/non-functional data) of any DLC is closed source or under non-free licence ?
just answer me simple

Hello, i was read all code of main program is free, but what about DLC ? Code of DLC's is free or non-free ?