On Fri, Jul 23, 2010 at 7:23 PM, Platonides <Platonides(a)gmail.com> wrote:
I think that's because they are more liberal
licenses, like MIT*. Do we
have any code that isn't GPL-compatible?
*To which extent they can do that is debatable. Maybe they can only
license under that license *some* pieces of their code.
There are at least some pages on
mediawiki.org for extensions that are
not under any open-source license at all. I remember at least one
case where an extension there was only available as commercial
software, and other developers in #mediawiki disagreed with my opinion
that it should be deleted.
I consider that completely unrelated. PHP is a
platform, similarly as
how you can use a non-GPL program on a GPL kernel. Or write a document
on a GPL text editor without it being automatically open source.
Insofar as PHP is just a program that processes input files, yes. But
it also includes a standard library. If the PHP standard library
implementation were licensed under the GPL, then at least according to
the FSF's interpretation, it would be forbidden to write non-GPL
programs for it. That's why OpenJDK (at the advice of the FSF) is GPL
with a special linking exemption -- without the exemption, all
programs written for it might have to be GPL. Likewise the GNU C
standard library is licensed under the LGPL, not GPL.
Of course, in some of these cases there are non-GPL implementations
too, and if you write it to be compatible with multiple
implementations, I don't think anyone argues that it's a derivative
work of any of them . . . I'm still not clear on this point. But in
any event, I don't see why there'd be a difference between a library
that happens to be shipped with a programming language implementation,
and one that's not.
It wouldn't need to be under GPL. AFAIK, the case
for that is that
kernel drivers usually copy code from the GPL ones. Also note that since
some version, they have apis not available for closed drivers.
I think there are some interesting discussions about this on lkml archives.
Linus Torvalds, at least, thinks that some drivers intrinsically need to be GPL:
http://lkml.indiana.edu/hypermail/linux/kernel/0312.0/0670.html
I don't know whether his view is correct, but it's certainly prevalent
in the Linux kernel community, from what I've seen.