On Sun, Apr 10, 2011 at 9:45 PM, Aviad Mandel <[email protected]> wrote: > On Sun, Apr 10, 2011 at 8:28 PM, Oleg Goldshmidt <[email protected]> wrote: >> >> This looks to me (reminder: IANAL) as a rather simplistic attempt to >> circumvent GPL. I cannot believe that this trick is legal. > > I'm likewise skeptic. But if this is illegal, and I don't understand why, > then there's still an important lesson to learn.
The lesson is that you focus on technical tricks in the (futile) hope of avoiding the intellectual property question. You have a GPLed library A and proprietary code B. Is B+A a derivative work of A or not? No amount of technical trickery (writing a wrapper for the GPLed API, distributing B and A separately and asking the customer to o the linking, whatever) should be enough to change the answer from "yes" to "no" (barring a serious legal hole in GPL). >> 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"? > > My question is: Does it matter? Business B owns the B part, so it doesn't > need any permission to distribute the code. Yes, it does, if B is a derivative of A, e.g., will not work without A. In my earlier example, business B will not need A's permission to sell a microwave oven (that will not need A), but will need such permission to sell a voice-controlled oven that uses A to implement voice control functionality. Assuming the whole thing is a single piece (as it is likely to be in your case) the whole of B+A must be under GPL. B are free to use some other voice control library with a more permissive license, or forget about voice control - in both cases they can keep their code closed. But the cannot base the product on A and avoid GPL. > Part A can be distributed anyhow as sources, so there's no problem here > either. Nobody could claim that there's a problem distributing GPLed sources > alongside with anything. As a mere aggregation (both on the same CD), no, as a single piece of work that requires A, yes. > So where's the catch? Can a compilation be seen as a copyright infringement? No, only distribution (conveyance in v3), which is quite well defined, but you need to apply a serious effort to parse it. As Guy wrote, you are on shaky ground. I think you have been given enough food for thought that shows that there are issues. How important these issues are is out of your control - it is up to your customers to decide. GPL is a complicated license in practice, and I strongly suggest that you stop thinking in terms of "GPL for evaluation" - it simply does not accommodate the notion of a specific/limited purpose or scope. If you want to think in terms of a dual license then it's a different matter, and you will need to decide how it fits your business model. Again as Guy wrote, the Vendor A - Business B - Consultant C triangle will have many fewer problems if you choose LGPL rather than GPL. The problem that remains (among those already mentioned - there may be others) in this case is A's possible problem with Mr. C who may use A's code to directly compete with A. But Mr. A may decide it is OK, even though he won't necessarily know in advance who Mr. C is. -- Oleg Goldshmidt | [email protected] _______________________________________________ Linux-il mailing list [email protected] http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
