Fabien's open letter to the community

[yanquis1972]

what does any of that have to do with me??

do i wish houdini was tested universally & allowed on playchess? sure. nothing i can do about it though.

[alpha123]

Well this is interesting. Thanks Tord.

It sounds like Fabien believes Rybka has Fruit parts. Possibly a GPL violation. Who is the current copyright owner of Fruit 2.1? At one point I heard it was the FSF, and I'm sure they would be more than happy to go after the non-Free Rybka....

Peter

[mwyoung]

I only have one question. And this is for anyone.

Will playchess now ban Rybka from playing in the engine room?

[lmader]

still dont give a damn (or see why i should) if vas took open source code & improved it by 100+ elo. whether he charged or not

The reason that one should give a damn is that the Fruit code was made open source under a license - the GPL license. This means the code is free and open, but subject to the restrictions in that license. If Rybka contains code from Fruit, there are aspects of this license that would be violated. For example, I believe that one of the terms of a GPL license require that any software that uses the code remain open source. There are reasonable grounds for lawsuit _if_ it can be proven that there is code from Fruit in Rybka, and if anyone cared to pursue one.

And proving that point is difficult.

[Mike S.]

I find this to be especially noteworthy:

First there was the Strelka case. (...) The short answer was "no", it was not a verbatim copy of the source code. All the code had been typed (can't say "designed" though, see below) by an individual. So legally there was no issue that I knew of. It was however a whole re-write (copy with different words if you like, similar to a translation) of the algorithms. Not just an extraction of a couple of ideas as is common, and normal.

That being said, some original changes and ideas were also included in the program. (...) Edit: I've just had a look at the 2.0 sources. On top of what I said above, there are many constant and function names that are identical to Fruit's. I remember noticing it back then as well.

This means (to me), there is most probably an ethical issue or case "Fruit versus Strelka(1)", but not a legal one between these two. This distinction should be made for precision of discussion. Also, we don't have to assume necessarily that Strelka 2.0(!) is identical in that respect, to any Rybka. But as for the initial, first Strelka and Rybka 1.0 beta, I remember that a couple of identical bugs and/or output (considering depth+2) e.g. in strange positions were posted here. That didn't leave any room for doubt IMO.

Of course, having no direct copy & paste from Fruit into Strelka (considered to be based on re-engineering from a binary) doesn't prove that there is no copy & paste Fruit code in Rybka 1.0. But it also doesn't prove the opposite!

Anyway, if code was not "taken directly" like in copy & paste but rewritten, then I guess there are no legal issues in terms of licenses and/or copyright, but certainly a question of ethics... Or whatever; it doesn't make sense to me: Since Fruit was open source up to 2.1 IIRC anyway, wouldn't it have been possible to include Fruit code legally even into a commercial engine? AFAIK this is possible even with keeping the other parts' code closed if the open source code is published/distributed with the engine, with it's changes for the implementation, and the GNU license. If I understand this matter right, this would be the correct way.

As for Houdini, the questions are similar with the difference that it isn't a commercial engine (yet?). By the "in dubio pro reo" principle, we can assume that existing open source code - which may be of ethically questionable origin itself though - was utilized by taking ideas and (re-)writing code, maybe "very closely" sometimes...

(We can also assume, or imagine anything else.)

In case of copy & paste of GNU open source code, it seems clear to me that at least the code parts resulting from that, need to be published in compliance with the GNU license to ensure legality.

The whole matter looks like a crazy vicious circle if you e.g. think of the Ippo/Robbo/Fire makers now must suspect that their (? highly debated) open source engine might have ended up in a proprietary "closed" engine stronger than theirs...

A mess!

[PauloSoare]

Things got ugly. And now, what will happen?

[tomgdrums]

Well, it looks like I am going to have to delete Rybka 3 and Rybka 4 from my computer. I am not being facetious either.

On principle I have stayed away from the Ipps and Houdini and now to stay principled I am not going to be able to continue using Rybka.

Makes me sad, but that is the way it is.

(it actually makes me a little angry as well since I paid for Rybka...I wonder if I can get my money back?)

[mwyoung]

Well, it looks like I am going to have to delete Rybka 3 and Rybka 4 from my computer. I am not being facetious either.

On principle I have stayed away from the Ipps and Houdini and now to stay principled I am not going to be able to continue using Rybka.

Makes me sad, but that is the way it is.

(it actually makes me a little angry as well since I paid for Rybka...I wonder if I can get my money back?)

Nice to see you are going to be consistent and stand by your principles. I wonder if others will be consistent? Mr. Banks?

[Albert Silver]

Well, it looks like I am going to have to delete Rybka 3 and Rybka 4 from my computer. I am not being facetious either.

On principle I have stayed away from the Ipps and Houdini and now to stay principled I am not going to be able to continue using Rybka.

Makes me sad, but that is the way it is.

(it actually makes me a little angry as well since I paid for Rybka...I wonder if I can get my money back?)

I don't agree. Even in a worst case scenario, where there is incontrovertible proof of wrong-doing, the buyer who acted in good faith is never legally or ethically liable.

Suppose, for example, that Intel is proven today to have ignored patents owned by some guy on key components in the CPU you have in your machine. Is your only ethically correct course to remove the CPU and toss it out the window? Of course not. The guy (in this hypothetical situation) can sue and get his due and that is that. Whatever money you the buyer spent that went to the wrong person would be redirected via the legal system. This burden of responsibility assuredly does not fall upon the buyer.

[tomgdrums]

Well, it looks like I am going to have to delete Rybka 3 and Rybka 4 from my computer. I am not being facetious either.

On principle I have stayed away from the Ipps and Houdini and now to stay principled I am not going to be able to continue using Rybka.

Makes me sad, but that is the way it is.

(it actually makes me a little angry as well since I paid for Rybka...I wonder if I can get my money back?)

I don't agree. Even in a worst case scenario, where there is incontrovertible proof of wrong-doing, the buyer who acted in good faith is never legally or ethically liable.

Suppose, for example, that Intel is proven today to have ignored patents owned by some guy on key components in the CPU you have in your machine. Is your only ethically correct course to remove the CPU and toss it out the window? Of course not. The guy (in this hypothetical situation) can sue and get his due and that is that. Whatever money you the buyer spent that went to the wrong person would be redirected via the legal system. This burden of responsibility assuredly does not fall upon the buyer.

Well a CPU is a much more high dollar investment and therefore it is rarer for things to get THAT far because of all the money involved. And NO I would wait on the CPU and try to get my money back first before tossing it. Reasons? 1) The Computer is essential to my everyday work and therefore I would have to wait for restitution and a suitable replacement. But once that happened..yeah it is gone!

Now with a chess engine it is NOT essential to my everyday work or living. And it is a small dollar item when compared to an entire computer. It is not okay for Vas to have done the same thing that others are being accused of. I have not used the other questionable engines and NOW can no longer use Rybka. I can not live by a double standard.