Subject: Re: dumb GPL question
From: Bernard Lang <>
Date: Wed, 6 Jun 2001 16:54:23 +0200

Thanks to all who replied,

  it helped me reread the GPL ... my view having been obviously
distorted over time by reading too many comments on it.

  My concern was that one is not allowed to extend a GPL program with
non-GPL parts, or include GPLed parts in a non GPL program.

  But what if I want to create a GPLed something that includes non-GPL
parts (assumed to be freely usable and distributable, but not
necessarily free), which are not part of the underlying operating

   Apparently, I can only assert the source code as GPL.
   Can I distribute an executable version ?

This is more or less Stephen's question below.

   The original author can, since he can actually do what he pleases
with his own work.

But since the next person cannot comply with the terms of section 3 of
the GPL licence (part of the code being under another licence) where
distribution is concerned, he cannot (copy !? and) redistribute the
object code of the work, though he can freely modify and redistribute
the source as GPL.

  But the author could well make a licence GPL' that is GPL without
the constraining requirement that prevent redistribution of object
code (requiring the source only for the original part), together with
a permission to distribute the source as GPL (which would in practice
remain moot w.r.t. executable code as long as the non-GPL parts are
not rewritten as GPL).

   In other word, get the same effect as the GPL, but be able to
specify what part of the system source is or is not covered by the GPL
(and probably forbidding functionnal extensions of the non GPL parts
to avoid cheating ... and this is were time ordering will matter).

  I am not sure I make sense ?


PS  Is "GPL for Dummies" published anywhere ?
   I am half serious with this question ... 

On Wed, Jun 06, 2001 at 03:50:50PM +0900, Stephen J. Turnbull wrote:
> >>>>> "Bernard" == Bernard Lang <> writes:
>     Bernard> is it OK to link GPL code to preexisting non-GPL code
>     Bernard> (for example a library) ?
> Yes, for personal use.  No, if the license of the code prevents
> redistributing the library under the GPL.  (There are exceptions for
> system software, namely libc, libX11, and libXm (Motif).  All others
> please ask  Cf. Aladdin Ghostscript and libreadline.
> It is legal to redistribute a binary compiled from GPL code and linked
> to some kinds of non-GPL free software, eg, public domain and X
> licenses, as long as the source for the library can be redistributed
> under the GPL.  (Hm.  Another dumb question.  Does the GPL require that
> #include <gnome.h>
> main () { gnome_printf("Hello, world"); }
> include all source to GNOME and GTK+ in its distribution?  You're not
> allowed to use 3c to escape.)
>     Bernard> else, how can one write GPL code in a non-GPL language ?
>     Bernard> (i.e. a language with no GPL implementation, especially
>     Bernard> of the run-time library, even though it may be
>     Bernard> open-source)
> This should escape under the "system library" rule in some cases if
> the compiler (a) is distributed as a standard part of the operating
> system and (b) its runtime library only provides the API to "the
> usual" system functions.  Ask RMS.
> Otherwise, it's arguable that you cannot.  RMS forced Aladdin to
> remove all code and support (eg, Makefile rules) for building Aladdin
> Ghostscript with libreadline, because the latter is GPL.  The argument
> was that the shim code and Make rules were simply a way to avoid the
> intent of the GPL, and thus making the end-user an agent of Aladdin.
> So the same argument might apply to writing a program in a language
> that requires linking with a non-GPL runtime library, and distributing
> as source code.
> The whole point of the GPL is to provide incentives for (a) the vendor
> of the non-GPL software to rerelease under GPL or (b) third-parties to
> reimplement and release under GPL.
> -- 
> University of Tsukuba                Tennodai 1-1-1 Tsukuba 305-8573 JAPAN
> Institute of Policy and Planning Sciences       Tel/fax: +81 (298) 53-5091
> _________________  _________________  _________________  _________________
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