Hello, i am in the process of forking an old version of GNU troff, starting from the last commit that is still GPL2 licensed (1.19.2-574-gecbf4f1). It is yet nothing but a bubble full of air, of course. (It will be S-roff.)
I planned to place all completely new code (like file_case) under the ISC license instead of the GPL2, which seems to be possible according to GPL2, is this understood correctly? So whereas S-roff has to be GPL2 licensed because it is a fork of GNU troff v1.19.2 such new parts, even though deeply embedded into the machinery, can be placed under the ISC license? S-roff will be a heavily stripped down version with a completely different build system, with heavily changed manuals etc., but still this condition is true? I'm also a bit uncertain because of the thread of Ingo and Bernd today, what licensing issues exist with small modifications i apply here and there? I want to place my own copyright header in all files of course, but i would like my changes to be covered by ISC instead of GPL2 -- i would be fine with Public Domain for that (see next paragraph), but i'm a bit afraid of missing disclaimers for these parts of the code then, so would it be ok to say something like "changes copyright [ISC license]"? And then, should a future GNU troff maintainer like some of the modifications i've implemented, will reintegration be possible when the fork is instrumented like that? Or does GNU still need a special Public Domain clause? Can i simply extend the mentioned "changes" accordingly? Thanks for any advise. --steffen
