GPL and closed source

[Tzeng, Nigel H.]

On 6/6/11 3:29 AM, "David Woolley" <forums at david-woolley.me.uk> wrote:

>Dale wrote:
>> 
>> GPL code <----> non-GPL but (GPL compatible) open source library <---->
>> closed source dll
>
>This decomposes as either
>
> > (GPL code <----> non-GPL but (GPL compatible) open source library
>)<---->
> > closed source dll
>
>in which case the first group has to be under the GPL, or
>
> > GPL code <----> (non-GPL but (GPL compatible) open source library
><---->
> > closed source dll)
>
>in which the second group is no longer GPL compatible, so even for
>mathematicians it doesn't work.

If the work is an aggregation why would the second group not be GPL
compatible?

If I write a GPL program that uses a BSD graphing package where
proprietary plug-ins (additional graph types, renderers, skins, whatever)
are available why would that BSD graphing package not be GPL compatible?
Because someone has the ability to buy a proprietary plug in for it?

As to whether the work is an aggregation reverts back to the deliberate
confusion regarding what is or isn't a derived work.