Gian-Carlo Pascutto wrote:I'm not so sure about the easily myself, but if you think it's easy to determine, I have to ask:
Is Rybka a derivative work of Fruit in your opinion?
Is Ippolit a derivative work of Rybka in your opinion?
Maybe you've made clear statements about this before. In that case, I might have missed them in all that discussion.
I cannot possibly know, as I don't have Rybka. When I say 'easy', I mean 'easy' on the scale of engaging in a lawsuit. So I assume that before suing they would be willing to go to the trouble of buying a copy of the involved Rybka version to submit it as evidence, and do the comparison on that. It would look a bit bad, I suppose, if they were making this claim based on an illegal copy of Rybka... I am sure people at the FSF are pretty adept at recognizng code from binaries. It is their business, after all.
Once the case goes to court, things become even simpler. To defend against a credible allegation, the accused part would be forced to produce source code for his defense, and anyone could compare that.
For Strelka vs. Fruit it is indeed very easy for all of us, as they are both released as source code.
Which of course does not mean that I have actually done it, or even that I am prepared to do it. I am not really interested in the answer, as none of the inolved engines holds any appeal to me, and I have more important things to do.
But from what I heard from people that seemed to have made a serious effort to dig up the truth, my current opinions on this are:
* Rybka is a legal derivative of Fruit
* Ippolit is an illegal derivative of some later Rybka