GPL and Python modules.

[Scott Robinson]

On Mon, 25 Oct 2004 20:13:46 -0700, Robert Kern <rkern at ucsd.edu>
wrote:

>Tim Churches wrote:
>> From: python-list-bounces+tchur=optushome.com.au at python.org 
>> 
>>>[mailto:python-list-bounces+tchur=optushome.com.au at python.org]
>>> On Behalf Of Robert Kern
>>>Sent: Tuesday, 26 October 2004 11:34 AM
>>>To: python-list at python.org
>>>Subject: Re: GPL and Python modules.
>>>
>>>
>>>Tim Churches wrote:
>>>
>>>>On Tue, 2004-10-26 at 11:12, Robert Kern wrote:
>>>
>>>>>Whether just using system calls is simply "normal use" for a GPLd OS
>>>>>kernel or this is simply a special exception to the GPL for 
>>>
>>>Linux only 
>>>
>>>>>is something that a court will have to decide. But such a 
>>>
>>>suit would 
>>>
>>>>>have to be about some other GPL kernel, not Linux.
>>>>
>>>>
>>>>Looks like it is a special exception for the Linux kernel 
>>>
>>>(or whatever 
>>>
>>>>other Linux code is distributed with this COPYING file. 
>>>
>>>Doesn't apply 
>>>
>>>>to other GPLed code.
>>>
>>>Well, not necessarily. It certainly isn't phrased as one. It 
>>>is at least 
>>>a statement of someone's (Linus's?) belief that standard applications 
>>>that only use system calls and running on Linux are not 
>>>derivative works 
>>>with respect to Linux.
>> 
>> 
>> Yes, so it is a specific exemption to the GPL granted by the copyright
>> holder(s) of the Linux kernel code. The GPL allows the copyright holder to
>> grant exemptions to the GPL privisions as they see fit - but no-one else.
>
>It's still phrased as Linus's interpretation of what constitutes a 
>derivative work and what constitutes normal use of the GPLed kernel. 
>He's specifically saying that userland applications are not derivative 
>works not "even though they are derivative works, they are excepted from 
>the requirements of this license."
>
>>>Are Windows programs actual derivative 
>>>works of 
>>>the Windows kernel? Does the Windows EULA make a statement about the 
>>>derivative status of applications?
>> 
>> 
>> No, and no. An important point of difference between the world views held
>> by, say, Steve Ballmer and, say, Richard Stallman.
>
>The world views of Ballmer and Stallman are irrelevant to whether 
>something is a derivative or not. They may be relevant to whether one 
>may get sued or not, but that's a different issue.
>
>In any case, Stallman does not appear to believe that userland 
>applications are automatically derivative works of the kernel:
>
>http://www.fsf.org/licenses/gpl-faq.html#GPLInProprietarySystem
>
>"""If the two programs remain well separated, like the compiler and the 
>kernel, or like an editor and a shell, then you can treat them as two 
>separate programs--but you have to do it properly."""

I would be careful in taking legal advise from Richard Stallman.  The
GPL merely states that*:

 	 2. You may modify your copy or copies of the Program or 
	any portion of it, thus forming a work based on the Program,
	and copy and distribute such modifications or work under the
	terms of Section 1 above, provided that you also meet all of 	
	these conditions:

After that, all notion of "derived work" falls on the appropriate
copyright law of the country in question.  I suspect that following
Stallman's verdicts won't cause you to violate the GPL, but I would
hardly be willing to be certain about going to court over a GPLed
module imported into an unfree python program.

Scott Robinson

* note that I believe that this is fair use.  According to the GPL,
you can only distribute it unmodified.