[License-discuss] GPL and proprietary WebAPIs

[Clark C. Evans]

On Sun, Dec 25, 2011, at 10:22 AM, Ben Tilly wrote:
> The real question is not what the GPLv3 does or 
> does not allow, it is what copyright does or does 
> not allow.  If a work is derived under copyright 
> law from a GPLed piece of work, then it must be GPLed.  
> If a work is *not* derived under copyright law 
> from a GPLed piece of work, the GPL is going to 
> have trouble restricting it.  If you write any
> other copyright license, you'll run into the same issue.

Thank you kindly for your response. 

My question involves 3 works, not 2.  We have a original 
work O, a "derived" work D (O + a shim/adapter), and an 
independent proprietary work P; where D derived from O 
under copyright law, D relies upon P for its operation, 
and where P has no substitutes.  I am assuming that by 
copyright law the author of O can restrict the distribution 
of D.  Let's further assume that P has no substitutes, so
that its functionality is not available under a license
compatible with the GPLv3.  So, my question is if the GPLv3 
would restrict the distribution of D due to its dependence 
on this independent and proprietary work P.

This is the essence of the WebAPI hack to the GPLv3, you
refactor your would-be derived work D into an independent
and proprietary work P as well as a shim S, such that
the "derived work" is D = O + S is released under the 
GPLv3 but the functionality "added" to O are effectively
useless unless you use it in conjunction with P.  This is 
exactly the case I discussed in my reply to Chris Travers 
and the shim technique promoted by Sybase's Kleisath [1].

It is my personal view that the GPL would absolutely 
restrict this since it covers "the whole of the work, 
and all its parts, regardless of how they are packaged",
"all the source code needed to [...] run the object code",
and "independent works, which [... are... ] combined".

What confuses me and what I'm asking here is why licensing 
professionals focus on two items that I consider irrelevant: 
(a) what is the type of linking between D and P? and 
(b) is D a derived work of P?   What we know is that D 
is derived from O and that D requires P for its operation.
Those two facts seem sufficient for my taste.

Best,

Clark

[1]
http://iablog.sybase.com/kleisath/index.php/2009/02/how-to-interface-proprietary-code-with-gpl-code/