Neil Santos wrote:
While mulling over a confusing part of something I'm writing, I decided to browse the info pages of GPC. In the GNU section, I read this:
When you modify a free program released under the GNU General Public License, e.g. the GNU Pascal compiler itself, your modified [work] will become Free Software, too.
I'm no lawyer, but I've read enough of RMS's articles regarding the GPL, as well as a few technical (but not necessarily legalese) discussions of the same, to understand that, when modifications to Free Software DO NOT need to become free themselves.
As I understand it, modifications to Free Software do not need to be released; but when it is, it HAS to be released under the GPL, if the program modified was released under the GPL.
[CC'd to RMS, in case I goofed, and therefore should be banished from society and be forced to use nothing but proprietary software.]
Since there was no reply so far: IANAL, but AFAICS, the main question is whether unreleased software (which is a derivative of GPL work, but wasn't put under the GPL) can/should be called free software, or whether this question is relevant at all (-; since the only one who has to the software at all also has the freedoms).
Anyway, Peter Gerwinski (who originally wrote the above paragraph) suggests the following clarification:
[...] 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.
Frank