Fabien's open letter to the community

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Tord Romstad
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Fabien's open letter to the community

Post by Tord Romstad » Sun Jan 23, 2011 9:13 pm

My good friend Fabien Letouzey, author of Fruit, asked me to post the following message for him:
Hello,

Long time no see.

First, I am not back to computer chess, sorry about that. I just want to clarify a few things. Sorry if that's old but there is some misunderstanding I need to fix, and I found out only yesterday. Bear in mind that I am mostly unaware of what has happened for five years though.

First there was the Strelka case. Dann approached me with some "Strelka" source code for me to check. I had never heard of it. I assumed it was some closed-source free engine and that people wanted to know whether it was based on the Fruit source code.

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. So it was, as has since been stated many times in fora I suppose, a bitboard re-write of Fruit with some personal (or otherwise) ideas. Also note that the source code Dann sent me might not be the from the 2.0 version.

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.

Hope it helps, because my email answer to Dann was unusually short and cryptic even by my standards. And Dann, please next time make it clear when you want a public statement instead of a private opinion, thanks.

I want to point out something immediately: there was no mention of Rybka whatsoever. Indeed I was unaware of any relation between Strelka and Rybka, this is precisely what I learned only yesterday. I insist because it seems I have often been quoted about "not caring" about the (possible) Fruit/Rybka relationship, but this is not so. Strelka did not look like a problem because I assumed it was free.

Next, I was approached by Ryan (I think) and Christophe Theron about whether I could help with some "possible Fruit code inside Rybka" issues. I answered "yes, but how?", but did not get a reply. This did not make me really aware of a clone possibility however because I thought they were talking about some insignificant UCI-handling code or whatnot. Also this was several years after the initial Rybka release, and I guess quite a few people had a close look at it. Apparently Chrilly did?

Now if someone could tell me a bit more about the major events last five years and the current state of affairs, I'd be much obliged.

A few things I noticed yesterday, can you confirm?
- Rybka search info was obfuscated in some way (like displaying depth-3 or something), any pointers on details please?
- Vasik claimed that Strelka 2.0 is a clone of Rybka 1.0 (and you know what that would imply!)
- Zach Wegner found many Fruit ideas (and nearly identical code) in Rybka 1.0; I think someone else did, too
- Some even stronger open-source program appeared as a decompilation of Rybka (with own ideas, sounds familiar), what came up of looking at those?

Any questions, now is the one time to ask.

Thanks for your attention,

Fabien Letouzey.

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JuLieN
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Re: Fabien's open letter to the community

Post by JuLieN » Sun Jan 23, 2011 9:22 pm

Oh boy, that's huge!

I tended to get annoyed by people throwing mud at Vasik, but if it comes from Fabien it is as if it comes from the mouth of the horse. Now Vasik REALLY has to provide Rybka 1&2 source code to a trusted authority of the community for comparison with Fruit. Not doing it will be considered as agreeing with Fabien's claims.
"The only good bug is a dead bug." (Don Dailey)
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AdminX
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Re: Fabien's open letter to the community

Post by AdminX » Sun Jan 23, 2011 9:23 pm

Thanks so much for sharing this! :D
"Good decisions come from experience, and experience comes from bad decisions."
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Ted Summers

bhlangonijr
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Re: Fabien's open letter to the community

Post by bhlangonijr » Sun Jan 23, 2011 9:29 pm

Tord Romstad wrote:My good friend Fabien Letouzey, author of Fruit, asked me to post the following message for him:
April fool's day?! I think not! :)

What a nice news. I noticed he (Fabien) had registered in this forum recently.

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Ozymandias
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Re: Fabien's open letter to the community

Post by Ozymandias » Sun Jan 23, 2011 10:10 pm

"there was no mention of Rybka whatsoever. Indeed I was unaware of any relation between Strelka and Rybka, this is precisely what I learned only yesterday"
Now you get up to date? Fabien, do you have enough space for another one in your cryo-chamber? :lol:

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fern
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Re: Fabien's open letter to the community

Post by fern » Sun Jan 23, 2011 10:38 pm

So:

If Strelka is partially a criature coming from Fruit -with some extra ideas- AND Strelka we already know is a very loyal copy of Rybka,

THEN:


Rybka should be considered also a partially criature coming from Fruit.

Who is first in this twisted history?:
a) Fruit
b) then Rybka is inspired by it
c) then Strelka is inspired by Rybka

What a vamp dance!!!
Tomorrow I will begin writting a book called Punishment and Crime.


Fern


Fern

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JuLieN
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Re: Fabien's open letter to the community

Post by JuLieN » Sun Jan 23, 2011 10:41 pm

fern wrote: Tomorrow I will begin writting a book called Punishment and Crime.
Good... that will be a nice sequel to the "War and War" this forum is writing since a few years. ;)
"The only good bug is a dead bug." (Don Dailey)
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Roger Brown
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Re: Fabien's open letter to the community

Post by Roger Brown » Sun Jan 23, 2011 10:43 pm

Tord Romstad wrote:My good friend Fabien Letouzey, author of Fruit, asked me to post the following message for him:


Hello Tord,

You certainly do not deliver the little bombshells do you?

:-)

Were you able to ask Fabien how he is doing?

A p.m. would be perfectly acceptable in response.

Later.

IWB
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Re: Fabien's open letter to the community

Post by IWB » Sun Jan 23, 2011 10:50 pm

Thanks for the info Tord.

Actually this should be moved to the engine origins subforum, but as this is shading a different light on the whole cloning issue of the last years it might be that the subforum should be redirected here again ... !

I think it is real fun, you have to be deep in the "facts" to understand the whole soap opera but if you are, it is entertainment at its best! the best that the humble users can do is lean back and enjoy!

One personal thing: It seems GPL, at least for chess, is dead as no one gives a ... somerhing for it.

Bye
Ingo

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slobo
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Re: Fabien's open letter to the community

Post by slobo » Sun Jan 23, 2011 11:15 pm

Thanks, Tord, for this post.
And also thanks to Fabien for his definitive and undubious clarification.
"Well, I´m just a soul whose intentions are good,
Oh Lord, please don´t let me be misunderstood."

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