Lots of excellent info, thanks everyone. So far the basic answer appears to be "no one knows, because the definition of derived is too vague".
I'm still a little curious about it though. I assume that writing a shell script that calls GPL'ed code is OK, right? Even if that shell script is not made public? I can see no difference between a GUI shell and a shell script in this specific regard. If I may redirect it a bit, is it up to the author of the tool in question? I'm specifically curious about dpkg, if I have written concent from the authors in question to build a GUI shell is that OK regardless of the vagrity of the license in this regard? And who _are_ the authors in the case of GPL'ed code? Maury
