Thoughts...

[Rolf]

I suspect that you know more about the GPL than I do. My understanding is that if you restrict your use of GPL material to private use, you do not have to publish the code. However if you release something to the public you have to include source code with it. Ryan released Fruit to the public and therefore the code is also available to the public without his permission. Is that correct?

Please read my post above. A commercial Fruit would hardly have been possible if it had to be published together with sources. When Fabien still had the rights he could modify the code and still sell it without GPL. This no longer is possible which seems fitting because Fruit is no longer a commercially maintained program.

I understood that he initially released it as freeware, then changed it to copy protected commercial and then released it as open source, under the GPL, when he decided to stop development.

If still unclear what I meant with "above", I only made one other post, I meant the post directly above your post where I responded to Uri explaining that Ryan had a license from Fabien Letouzey that goes above the GPL, to be able to make closed source releases of Fruit if he wishes, and he still has that.

I don't exactly recall if the first Fruits were without license, I suppose you are right about that. But the second phase in the life of Fruit was I believe the GPL one for Fruit 2.1 as last version, and it is this version which we all could still use under the GPL and on which for instance all the Toga versions are based. When however other programmers protested, that this GPL did not really give the protection Fabien had wished to have against commercial (ab-)use and closed source use by others, a fact which maybe is still relevant in our Rybka discussions, Fabien decided to go commercial with his program. I am not totally clear what his intentions were when he did that, on my part it would only be speculating, but I saw it as a way for him to continue with his program while no longer being bound to the GPL licensing which in the case of Toga and others were a bit disappointing for Fabien. He got the blame for all the clones, legal and illegal ones which, because the Fruit code was so good, were by many considered the bane of the idea that computer chess programming is an individual sport, where every programmer has to write all his code himself without any copying and especially direct code-copying. A bit anathema to the whole open source idea if you ask me but people felt the clones where everywhere and destroying their sport.

The GPL probably did not really offer practical protection against clones, only in case of commercial abuse the FSF can act (This is just my amateur interpretation, I'm no software expert or anything)

But back to Fruit, the commercial phase was also Fruit's third lifecycle but it did not change anything about the GPL conditions for Fruit 2.1, which are still the same for everyone today and still would apply to Rybka also:

No code taken directly from Fruit 2.1 should be in a closed program, the only exceptions are the commercial versions of Fruit by Fabien and Ryan together, starting with Fruit 2.2 and Fruit 2.2.1, not under the GPL, and any subsequent closed source versions from Ryan Benitez. But, if not closed source, the code can be used by the rest of us in GPL based open source versions of the code, like Toga, if correctly done with both sources and license, a mentioned and traceable author are I think also a necessity for the GPL to work, things like a code-changes list etc.

Since we know what Vas has said, could you now explain a bit what Vas has meant with public domain. How much could that be and could it also derive from Fruit, perhaps from one of the former versions? I dont seek legal advice, you dont decide huge flame wars with your answer now, but I just want to know a little bit more and with me many average members. Thanks in advance.

[sockmonkey]

Since we know what Vas has said, could you now explain a bit what Vas has meant with public domain. How much could that be and could it also derive from Fruit, perhaps from one of the former versions? I dont seek legal advice, you dont decide huge flame wars with your answer now, but I just want to know a little bit more and with me many average members. Thanks in advance.

Public domain code would be, for instance, the UCI interface code -- code which has been provided to the community for the purpose of implementing common interfaces, etc. Code found in GPL sources, if it is not this sort of public, license-free code, cannot be considered public domain, even if it's open source.

Which means that Vas is:
a) sincere (if potentially wrong/misinformed)
b) lying
c) referring only to Rybka 2 or Rybka 3, which potentially no longer has the controversial GPL'd code, rather than _all_ Rybkas, including Rybka 1.

Jeremy

[Eelco de Groot]

Since we know what Vas has said, could you now explain a bit what Vas has meant with public domain. How much could that be and could it also derive from Fruit, perhaps from one of the former versions? I dont seek legal advice, you dont decide huge flame wars with your answer now, but I just want to know a little bit more and with me many average members. Thanks in advance.

Hello Rolf,

You mean in Vas' reply

Once again: Rybka is 100% original at the source code level, not counting public-domain snippets like population cnt, etc.

Vas

It just means there are some methods that are more or less universally used, not directly related to a chess program, like methods for producing semi-random numbers or methods for counting the bits in a bitboard. Vas is just saying that he used some of these parts, without writing a totally original version himself.

The rest of Rybka he considers 100% his own code. This in my opinion would have to apply to all commercial Rybkas especially, Rybka 1.0 beta was free, so this is a bit of a grey area as far as GPL infringement (but it still would have to include sources if it was based on Fruit).

The point is just how much of the code is inspired by Fruit but not literally copied code and where would you put the margins between plagiarism of and being inspired by someone else's code. That is just not so simple to define, unless a lot of literal, i.e. identical code appears when you disassemble something (We don't have Vas sources to directly compare that with Fruit 2.1 so any comparison is indirect).

Eelco

[Rolf]

Once a year two grandmaster chess players had a game in the background
and two others were commenting the game.
Helmut Pfleger (ELO 2477) and Vlastimil Hort (2725).
The dialogue typically went like this:

Pfleger: Ah, black now comes out with a bishop. What can white do now?
Hort: Knight c5 looks good to me.
Pfleger: Knight c5? That is strange. But what if we play this. (Shuffles around
pieces on the demo board and shows the end position.)
Hort: Hm, ok but I like my knight.
Pfleger: Let's go back and try this (Shuffles around other pieces, explaining
possible attacks and defences.)
Hort: You may be right, but a knight on c5 ...
Pfleger: (Now moving the knight to c5 and wondering what pieces to move.) Hm?
Oh, there is the real move. Let's see. Knight to c5. ...
Harald

That's quote from H. Faber from Ruhrgebiet. I have it just before my eyes, it was part of a larmoyant description from several people about the representation of chess in German TV stations. The ill-meaning tone of the text above insinuates that someone like Pfleger and the whole couple of him with Hort ("Bierchen?") could allow to judge a rather low level, practically stupid nonsense. That is itself a lot of b/s. I dont want to go into details but Pfleger, a medical doctor, psychotherapist, has a huge skill to suck you into such a dry materia like chess.

[Rolf]

Since we know what Vas has said, could you now explain a bit what Vas has meant with public domain. How much could that be and could it also derive from Fruit, perhaps from one of the former versions? I dont seek legal advice, you dont decide huge flame wars with your answer now, but I just want to know a little bit more and with me many average members. Thanks in advance.

Public domain code would be, for instance, the UCI interface code -- code which has been provided to the community for the purpose of implementing common interfaces, etc. Code found in GPL sources, if it is not this sort of public, license-free code, cannot be considered public domain, even if it's open source.

Which means that Vas is:
a) sincere (if potentially wrong/misinformed)
b) lying
c) referring only to Rybka 2 or Rybka 3, which potentially no longer has the controversial GPL'd code, rather than _all_ Rybkas, including Rybka 1.

Jeremy

Now put this against what Eelco wrote. How you can compare the source code if you dont have it? Or how can you follow something else in your survey if it was claimed identical to the questioned program? Am I the only one who sees that this isnt just a question of skills in reading code? For all you must have the right code, no? Just questions. But if I can have them why not others here too? It would be sort of fatal if people only looked, ahem, Rolf is on this side, so, we can be surely on the right side if we vote for the opposite. But I cant do anything against such automatic reflexes.

[bob]

Professor Hyatt has already given one perfectly adequate reason why he sees no need to contact Mr Benitez and there may be others as well.

While I respect Bob's expertise, I would still suggest contacting Ryan in private to discuss the issue as being useful.

To what end? I (and several others) are quite capable of comparing programs. If Ryan sees no similarities, he is simply not looking very carefully. I don't need to ask anyone to interpret what I have seen, anybody that _wants_ to do this comparison can do it quite reliably, just as they could find copied paragraphs from one book used in another, once it has been pointed out.

Could you please describe what exact versions of what two progs you have compared? I think there could be the reason for such talks. Vas had said that Rybka contained 100% original code plus public domain. Even I can imagine what this means. Vas isnt stupid.

Fruit 2.1 and Whatever the original version of Rybka was. This has been covered about a hundred times.

I've not seen his comment about "public domain code" although if that references Fruit, that would be a GPL violation issue.

[K I Hyams]

Professor Hyatt has already given one perfectly adequate reason why he sees no need to contact Mr Benitez and there may be others as well.

While I respect Bob's expertise, I would still suggest contacting Ryan in private to discuss the issue as being useful.

To what end? I (and several others) are quite capable of comparing programs. If Ryan sees no similarities, he is simply not looking very carefully. I don't need to ask anyone to interpret what I have seen, anybody that _wants_ to do this comparison can do it quite reliably, just as they could find copied paragraphs from one book used in another, once it has been pointed out.

Could you please describe what exact versions of what two progs you have compared? I think there could be the reason for such talks. Vas had said that Rybka contained 100% original code plus public domain. Even I can imagine what this means. Vas isnt stupid.

Fruit 2.1 and Whatever the original version of Rybka was. This has been covered about a hundred times.

I've not seen his comment about "public domain code" although if that references Fruit, that would be a GPL violation issue.

- N/- By Vasik Rajlich (*****) [pl] Date 2009-12-01 09:10
"Once again: Rybka is 100% original at the source code level, not counting public-domain snippets like population cnt, etc".