GPL as an evaluation license

[Oleg Goldshmidt]

On Sun, Apr 10, 2011 at 7:43 PM, Aviad Mandel <aviad.mandel at gmail.com> wrote:
>
> Easy: Compile all Business B's sources into object files (.o, you know) but don't link. Send Mr. C the objects and sources Vendor A supplied. Tell Mr. C to compile and link the whole package (scripts, LiveDVDs whatever is needed to make this painless). Now Consultant C has a legal binary.

This looks to me (reminder: IANAL) as a rather simplistic attempt to
circumvent GPL. I cannot believe that this trick is legal. See also
below.

>
> But even this scenario isn't a threat, if the target market is microwave ovens one talks to. Unless someone puts a C compiler + linker on the oven's processor, to compile the code on its first use...

It's enough that there is a compiler and a linker on the development station.

>
> Corollary question: Given this situation, why should the binary distribution be disallowed to anyone having compilation / linking abilities? It's a bit like asking if I'm allowed to run a cracked version of software for which I have bought a license.
>

The notion of a "derivative work" is related to copyright, it does not
depend on whether you distribute the pieces separately or not, or on
who does the linking.

It looks to me that you suggest that Business B gives its code to a rd
party, and points the 3rd party to your website and says, you download
this GPL library from Mr. A, and you link. Since you didn't get the
GPL part from me and you do not "convey" the result, no one is in
violation and we can keep our code closed.

Typically, however, the B part will contain pieces that use the A
library - without those pieces the library will not be needed. The
rest is a legal (copyright) question: does this make B a "derivative
work"? Suppose Business B is in microwave oven business, and you,
Vendor A,  provide software that allows microwave oven to be
controlled by voice commands. In your scenario, Business B tells a 3rd
party, "You will get a voice-controlled microwave  if you take B.o and
link it with A.a". I suspect that a good argument can be made in court
that B.o is a derivative work under the circumstances and must be
GPLed.

Incidentally, I mix in GPL v2 notions here. The language of GPL v3 is
substantially different from v2 ("propagate" and "convey" rather than
"distribute", no explicit notion of "derivative work", etc.). I never
studied v3 at the same level of detail as v2. I implicitly rely on the
assumption that the spirit is the same or very similar, and that v3 is
not likely to be more permissive than v2. However, you've been warned.

--
Oleg Goldshmidt | pub at goldshmidt.org