[Zope-dev] ZPL and GPL licensing issues

[Jim Penny]

On Thu, Jun 21, 2001 at 05:18:40PM +0200, Federico Di Gregorio wrote:
> On 21 Jun 2001 11:08:30 -0400, Jim Penny wrote:
> [snip]
> > OK, consider this from another point of view.  If I have an operating
> > system may I install a piece of GPL software on the operating system?
> > May I redistribute the operating system?  With the GPL software?
> > May I invoke/run the GPL software?
> > 
> > My understanding is that the answer to every one of these is yes.
> 
> yes. only if it is free. only if it is free. yes, but only because gpl
> allows for gpl code linking with the major components of the os even if
> they are proprietary.

Uh, you might want to reconsider the "only if it is free" parts.  After
all Interix had a business of selling GPL software for a non-free
OS.  Now Microsoft has that business (NT Services for Unix Pack).
IBM distributes gcc and perl.  Cygwin sells GPL software for non-free
OS's.

> 
> > May I modify the GPL software and distribute it without giving
> > downstream the same opportunity.  Clearly no.
> > 
> > Now, s/operating system/zope/g
> > 
> > Do the answers to the questions change?  And, if so, why?
> > 
> > >From my perspective, and I think from fog's the answer is that
> > it should not change the answers.
> 
> err, no. if you write an external module using only python code, as long
> as you use a gpl-compatible python to run zope, you can call your
> external code from zope. if you write a product suclassing dc code,
> you're effectively 'linking' and gpl limitations apply. 

GPL limitations apply to whom:  To you, the developer?  To a
downstream user invoking the product via dtml-call or dtml-var or their
pythonish equivalents?  To a downstream developer who modifies your
product and redistibutes the modified product?  To a downstream
developer who writes a component that invokes the GPL component?

In my mind the only sensible answers are developer - no,
user - no (but see Jerome Alet's codacil), downstream modifier - yes,
downstream developer who uses - no.

The only other sensible option is that, indeed, no one may distribute
GPL components for Zope, including the original developer.

> 
> > Maybe the easy way out of this is to simply declare zope an
> > "operating system" rather than an "application".  Snippy
> > thoughts cut here.
> 
> eheh. nice try... :)
> 
> -- 
> Federico Di Gregorio
> MIXAD LIVE Chief of Research & Technology              fog@mixadlive.com
> Debian GNU/Linux Developer & Italian Press Contact        fog@debian.org
>                            Don't dream it. Be it. -- Dr. Frank'n'further
>