[ILUG] GPL clarification.

[Rick Moen]

Quoting Bryan O'Donoghue (typedef at eircom.net):

> >However, neither the GPL nor the LGPL either allow or disallow 
> >binary-only works to link to them. Both are framed in terms of requiring 
> >"derived works" to have source made available.
> 
> I'm ambiguious on the meaning here.
> 
> If libblah.a is GPL, and evilcorp does a
> 
> gcc -o marketable_binary_a propiatery_license.c -lblah
> gcc -o marketable_binary_b propiatery_license.c -Bstatic -lblah
> 
> does that imply that marketable_binary_a is then considered a derived 
> work and must be GPL'd ?

1.  The term in copyright law is actually "derivative work".

2.  Considered by whom?  Lots of people have some diverse (and often
    dubious) opinions about what is and is not a derivative work.  
    The matter is actually decided by judges, applying the statutory
    and caselaw of their jurisdictions.

3.  Neither the GPL nor the LGPL has any mechanism to force Evilcorp to
    make any particular management decision concerning marketable_binary_a.
    All they can do is, given that Evilcorp have accepted a copy of 
    libblah.a and used it in ways permitted only by that copy's attached
    terms of use, state that violation of those terms of use deprive 
    Evilcorp of the conveyed rights.  If Evilcorp exercise those 
    rights (e.g., the right to create derivative works or the right of
    redistribution) without permission, the net effect is that it they are 
    committing the tort of copyright violation, and would probably 
    lose any properly filed infringement action by the owners of 
    libblah.a's copyright title.


> As far as I understood it up until Liam's post, only if I for example 
> changed libblah.a and recompiled it and/or statically linked (not sure 
> about statically linking) then the 'modified' GPL'd code would have to 
> be distributed.

In no case can GPL or LGPL compel distribution or particular licensing,
as explained above.  All they can do is outline conditions under which 
certain otherwise-reserved rights are conveyed to recipients with the
attached instance of the covered software, by its copyright owner.