Re: [OctDev] No symbolic package in future (Windows/VC++) releases

[Jaroslav Hajek]

On Tue, Apr 21, 2009 at 11:16 AM, Michael Goffioul
<address@hidden> wrote:
> On Mon, Apr 20, 2009 at 10:51 PM, Judd Storrs <address@hidden> wrote:
>> On Mon, Apr 20, 2009 at 5:04 PM, John W. Eaton <address@hidden> wrote:
>>>
>>> Does the FAQ answer specifically say that you are not allowed to
>>> distribute them together?
>>
>> GPLv2 section 3 does:
>>
>> "However, as a special exception, the source code distributed need not
>> include anything that is normally distributed (in either source or binary
>> form) with the major components (compiler, kernel, and so on) of the
>> operating system on which the executable runs, unless that component itself
>> accompanies the executable."
>>
>> The question is whether being part of the same installer counts as
>> "accompanies the executable". GPLv3 may be more lenient. The best I could
>> find as equivalent is at the end of section 6:
>>
>> "A separable portion of the object code, whose source code is excluded
>> from the Corresponding Source as a System Library, need not be
>> included in conveying the object code work."
>>
>> It seems to me that the GPLv3's "need not" is much more permissive than the
>> GPLv2's ban on co-distribution.
>
> Just for the record, looking at the answer here
>
> http://www.ginac.de/pipermail/cln-list/2009-April/000513.html
>
> this guy won't stop at GiNaC/CLN. And he claims this is still
> valid for GPLv3.
>
> Michael.
>

I think it comes down to the fact whether MSVC++ runtime qualifies as
a "System Library".
See clause 1 of GPL3:
  The "System Libraries" of an executable work include anything, other
than the work as a whole, that (a) is included in the normal form of
packaging a Major Component, but which is not part of that Major
Component, and (b) serves only to enable use of the work with that
Major Component,

Major Component here is Windows. It seems to me the MSVC++ qualifies
under (b): it is clearly intended to only enable MSVC++ compiled C++
programs run at Windows, (unless you patch Octave to use
MSVC++-specific features).

If this is right (and prove me wrong), the next paragraph clearly
excludes this library from Corresponding source. I don't think the
paragraph containing the "aggregate" definition (Conveying Modified
Source Versions) is relevant at all.

It seems that GPLv2 is more strict and forbids the distribution, while
GPLv3 allows it. If GiNaC uses the standard "or any later version"
clause, then I think you can still happily distribute what you do.
What needs to be excluded from your distribution is GPL2-only software.

-- 
RNDr. Jaroslav Hajek
computing expert & GNU Octave developer
Aeronautical Research and Test Institute (VZLU)
Prague, Czech Republic
url: www.highegg.matfyz.cz