On 19:15 16/04/04, Waldek Hebisch wrote:
[...] If you choose to release it, it must be under the GNU GPL. or [...] It is not necessary to release it, but if you do so, it must be under the GNU GPL.
IMHO the clarification is less accurate then the original. GPL requires derivative works to be free software, but one can choose different licence for new parts (say MIT licence). In fact, one can invent
Peter Gerwinski's solution is optimal; however, we must note that, as Waldek does, that modifications to the GPC distribution done by adding entirely new files (without code already contained in the GPC distro) can be released under a different license.
But if we're going to do that, we'd also have to note that whether or not you'd have to use a GPL-compatible license depends on whether or not your entirely-new-files link with the whole distro (in which case it HAS to be released under a GPL-compatible license), or is designed to be used separately (in which case it can be proprietary).
Yes, I know I've opened a whole box of cans of worms. I'm sorry.
[P.S. John Ries has a follow-up on the topic, explaining why derivative works don't necessarily have to be free software; not even open source.]