[kaffe] Darwin license vs GPL

[Dalibor Topic]

Kiyo Inaba wrote:
> Hi,
> 
> So, if the comment in darwin derived code is correct, at least 'I' can
> not compile and link (in GPL terminology 'forming a work based on the
> Program') kaffe with darwin headers. The person who never made any mod
> nor distributed kaffe will get different situation, since the person
> need not to accept kaffe's license (of course GPL).
> 
> Are there any misunderstanding for the license issue in my observation?

Hi Kiyo,

The special exception for major operating system components in section 3
of GPLv2 lets you do that, as it takes such components like the kernel,
compiler, etc. out of the set of complete sources for the work. GPLv3
goes into a bit of more length on it under the 'System Libraries'
definition.

Header files for system libraries fall under it, as does the toolchain,
kernel, etc. i.e. you can build & distribute GPLd programs for
GPL-incompatible, and even proprietary operating systems.

Anecdotal evidence would be that the GNU project started out / was
bootstrapped on proprietary systems out of necessity, so it makes sense
to not limit GPLd works to just be usable with free operating systems.
Another piece of anecdotal evidence for this special case is that Apple
uses the GPLd gcc toolchain as their default toolchain for darwin (and
contributes back to gcc), and redistributes it with each copy of OS X.

> P.S. There is one rescue in APSL 1.1. Sec.7 gives me the freedom to 
>      select newer versions of APSL, and APSL 2.0 is thought as 'open
>      source license'. But still it is incompatible with GPL (at least
>      GPL 2.0).

Yeah, see http://www.gnu.org/philosophy/apsl.html for details.

cheers,
dalibor topic