GPL with linking exception?

GPL with linking exception?

[Guillaume Yziquel]

Hello.

I've been looking around on the net to see if I could find a GPL3 + 
linking exception copyright notice lying around. I only found LGPL + 
linking exception.

Does anyone know what to write for GPL3 + linking exception? Is it even 
possible, or is only LGPL + linking exception possible?

All the best,

-- 
      Guillaume Yziquel
http://yziquel.homelinux.org/

Re: [Caml-list] GPL with linking exception?

[Dario Teixeira]

Hi,

> I've been looking around on the net to see if I could find
> a GPL3 + linking exception copyright notice lying around. I
> only found LGPL + linking exception.
> 
> Does anyone know what to write for GPL3 + linking
> exception? Is it even possible, or is only LGPL + linking
> exception possible?

IANALNDIPOOTV (I am neither a lawyer nor do I play one on TV), but I'm
under the impression that the  linking exception only makes sense to
appease the requirements of LGPL.  The LGPL requires that the main binary
may be used with an updated version of the LGPL library, which in most
cases implies some form of dynamic linking.  However, this conflicts
with the most common way of building Ocaml programs, where all Ocaml
libraries are statically linked into the main executable.  Hence the
need for a linking exception, which relaxes the LGPL requirement.  If,
on the other hand, the library is GPL, then all source code is available
(library + main), which renders this point moot.

Best regards,
Dario Teixeira

Re: [Caml-list] GPL with linking exception?

[Guillaume Yziquel]

Dario Teixeira a écrit :
> Hi,
> 
>> I've been looking around on the net to see if I could find
>> a GPL3 + linking exception copyright notice lying around. I
>> only found LGPL + linking exception.
>>
>> Does anyone know what to write for GPL3 + linking
>> exception? Is it even possible, or is only LGPL + linking
>> exception possible?
> 
> IANALNDIPOOTV (I am neither a lawyer nor do I play one on TV), but I'm
> under the impression that the  linking exception only makes sense to
> appease the requirements of LGPL.  The LGPL requires that the main binary
> may be used with an updated version of the LGPL library, which in most
> cases implies some form of dynamic linking.  However, this conflicts
> with the most common way of building Ocaml programs, where all Ocaml
> libraries are statically linked into the main executable.  Hence the
> need for a linking exception, which relaxes the LGPL requirement.  If,
> on the other hand, the library is GPL, then all source code is available
> (library + main), which renders this point moot.
> 
> Best regards,
> Dario Teixeira

I acknowledge that you are not a lawyer, nor that you play one on TV.

To my understanding the LGPL requires that you be able to replace the 
LGPL'd library by another library (including an updated version of the 
library). To this extent, it (very roughly and very quickly) imposes 
conditions on the stub code interfacing the two libraries, and you need 
to be able to reproduce the compilation steps. Very roughly... I'm not a 
lawyer either. Nor do I play one on TV.

I do not believe (but I may be mistaken) that this conflicts with the 
static linkage of the main executable. But if you have the ocaml runtime 
getting linked in some way or the other, then the LGPL becomes somehow 
not very handy. Is this the main reason?

My question about GPL is mostly the following: Can you distribute GPL 
bytecode files? Do you have any issues when 'linking' the runtime with 
the GPL bytecode?

Or are there other issues preventing from releasing GPL OCaml code?

All the best,

-- 
      Guillaume Yziquel
http://yziquel.homelinux.org/

Re: [Caml-list] GPL with linking exception?

[Dario Teixeira]

Hi,

> My question about GPL is mostly the following: Can you
> distribute GPL bytecode files? Do you have any issues when
> 'linking' the runtime with the GPL bytecode?
> 
> Or are there other issues preventing from releasing GPL OCaml code?

If you want a waterproof lawyerly response you should consider contacting
an organisation like the Software Freedom Law Center [1].  Nevertheless,
IMHO I see no obstacle in using the GPL with Ocaml code, and there are
in fact plenty of Ocaml projects using this license.  Could you elaborate
on why you feel that the GPL could in theory prevent the release of Ocaml
code?

Cheers,
Dario Teixeira

[1] http://www.softwarefreedom.org/

Re: [Caml-list] GPL with linking exception?

[Guillaume Yziquel]

Dario Teixeira a écrit :
> Hi,
> 
>> My question about GPL is mostly the following: Can you
>> distribute GPL bytecode files? Do you have any issues when
>> 'linking' the runtime with the GPL bytecode?
>>
>> Or are there other issues preventing from releasing GPL OCaml code?
> 
> If you want a waterproof lawyerly response you should consider contacting
> an organisation like the Software Freedom Law Center [1].  Nevertheless,
> IMHO I see no obstacle in using the GPL with Ocaml code, and there are
> in fact plenty of Ocaml projects using this license.  Could you elaborate
> on why you feel that the GPL could in theory prevent the release of Ocaml
> code?

Well, you create a bytecode executable under GPL. You therefore include 
the OCaml bytecode runtime. You'd be distributing part of the bytecode 
runtime under the GPL, and I somehow feel there's a fish in doing so.

This is just a question I'm asking myself. I do not have a hard opinion 
on that. Im just asking to collect advice from people on this list who 
might have wondered the same kind of things. That's all.

All the best,

-- 
      Guillaume Yziquel
http://yziquel.homelinux.org/

Re: [Caml-list] GPL with linking exception?

[Stefano Zacchiroli]

On Sun, Jan 17, 2010 at 05:47:10PM +0100, Guillaume Yziquel wrote:
> Well, you create a bytecode executable under GPL. You therefore
> include the OCaml bytecode runtime.

Uh? Why "therefore"?

If you just distribute the bytecode (no -custom compilation involved),
you will be not distributing the OCaml runtime with it, just your own
program compiled to bytecode.

Cheers.

-- 
Stefano Zacchiroli -o- PhD in Computer Science \ PostDoc @ Univ. Paris 7
zack@{upsilon.cc,pps.jussieu.fr,debian.org} -<>- http://upsilon.cc/zack/
Dietro un grande uomo c'è ..|  .  |. Et ne m'en veux pas si je te tutoie
sempre uno zaino ...........| ..: |.... Je dis tu à tous ceux que j'aime

Re: [Caml-list] GPL with linking exception?

[Guillaume Yziquel]

Stefano Zacchiroli a écrit :
> On Sun, Jan 17, 2010 at 05:47:10PM +0100, Guillaume Yziquel wrote:
>> Well, you create a bytecode executable under GPL. You therefore
>> include the OCaml bytecode runtime.
> 
> Uh? Why "therefore"?

Because I was indeed thinking of -custom when talking about "executable"...

> If you just distribute the bytecode (no -custom compilation involved),
> you will be not distributing the OCaml runtime with it, just your own
> program compiled to bytecode.

Is it the only issue with the GPL? If that's the only issue, then it's 
perfectly fine with me...

All the best,

-- 
      Guillaume Yziquel
http://yziquel.homelinux.org/

Re: [Caml-list] GPL with linking exception?

[Stefano Zacchiroli]

On Sun, Jan 17, 2010 at 11:05:05PM +0100, Guillaume Yziquel wrote:
> >Uh? Why "therefore"?
> Because I was indeed thinking of -custom when talking about
> "executable"...

OK, but notice that -custom has been deprecated for a while now. Also,
it is not clear to me which benefit do you gain in distributing your
stuff that way: you lose portability (which is the main benefit of
bytecode) and you have slower code than native code. (Of course, it
might be that you don't have a native code compiler for your target arch
...)

> >If you just distribute the bytecode (no -custom compilation involved),
> >you will be not distributing the OCaml runtime with it, just your own
> >program compiled to bytecode.
> 
> Is it the only issue with the GPL? If that's the only issue, then
> it's perfectly fine with me...

IANAL, but anyhow no, it is not the only issue with the GPL, but this
issue is a more generic one. It boils down to what you distribute: if
you distribute only stuff written by you, you can choose the license, if
you distribute also stuff written by someone else (the bytecode compiler
in this case), than you have to care about runtime compatibility. Of
course the fact that you can choose the license does not imply that you
can actually run it against the bytecode interpreter, but AFAICT this is
not a problem that the GPL will induce.

Obviously, GPL-ed bytecode means that the source of the bytecode most go
along with it.

Cheers.

-- 
Stefano Zacchiroli -o- PhD in Computer Science \ PostDoc @ Univ. Paris 7
zack@{upsilon.cc,pps.jussieu.fr,debian.org} -<>- http://upsilon.cc/zack/
Dietro un grande uomo c'è ..|  .  |. Et ne m'en veux pas si je te tutoie
sempre uno zaino ...........| ..: |.... Je dis tu à tous ceux que j'aime