CODA now has a released page.

[Graham Banks]

I will summarize again the most straight-forward argument, since it seems some posters are having a hard time following the conversation.

- Coda recently changed the license to GPLv3.
- Coda contains code from Reckless and Viridithas.
- Reckless and Viridithas are licensed under the AGPLv3.
- The GPLv3 is not compatible with the AGPLv3, as it rescinds some obligations.
- By publishing AGPLv3'ed code, marked as GPLv3 code, Coda is attempting to re-license Reckless/Viridithas.

At least, the Coda co-author is prepared to address all of these concerns.
I guess once that's been done, you'll have no beef with Coda?

[AndrewGrant]

I will summarize again the most straight-forward argument, since it seems some posters are having a hard time following the conversation.

- Coda recently changed the license to GPLv3.
- Coda contains code from Reckless and Viridithas.
- Reckless and Viridithas are licensed under the AGPLv3.
- The GPLv3 is not compatible with the AGPLv3, as it rescinds some obligations.
- By publishing AGPLv3'ed code, marked as GPLv3 code, Coda is attempting to re-license Reckless/Viridithas.

At least, the Coda co-author is prepared to address all of these concerns.
I guess once that's been done, you'll have no beef with Coda?

If Coda can find a license that is compatible with all the engines digested, and then package releases with the appropriate licenses/notices, then I have no problem with Coda in particular. Adam is very clearly not a malicious actor in any way. His project just happens to be at the center of the broader conversation about LLMs and Licensing, since he is the first guy to make a serious effort in the computer-chess space.

I have no "conquest" against Coda specifically -- in contrast to the conquest against Fire/Houdini.
Some users here have suggested otherwise, but they have misread or misinterpreted my motivations.

[jasper.sinclair]

I have no "conquest" against Coda specifically -- in contrast to the conquest against Fire/Houdini.
Some users here have suggested otherwise, but they have misread or misinterpreted my motivations.

your 'conquest' ? yes I see where you're coming from, comparing yourself to...
https://en.wikipedia.org/wiki/Spanish_c ... tec_Empire

[jasper.sinclair]

I'm a bit curious as to why you have only responded to "Ethereal's syzygy.c is not an original implementation"

Does the ethereal chess engine use any code and/or ideas from stockfish? Looking for a short and concise answer, not an extensive analysis.

ChatGPT: "Yes. Ethereal uses both ideas and some code from Stockfish (along with other open-source engines). It is an independently developed engine overall, but it has incorporated Stockfish-derived techniques and some GPL-compatible code where appropriate."

Can you be a little more specific?

ChatGPT: "Syzygy probing in Ethereal is derived from Ronald de Man's Syzygy probing code, just as in Stockfish. That's explicitly acknowledged.
Over the years, Andrew Grant has also imported specific search heuristics from Stockfish (LMR formulas, pruning tweaks, etc.), but those are often reimplemented rather than pasted.
There are utility components where the line between "rewrite" and "copy" is much blurrier. Some small modules are essentially the same design with C syntax instead of C++.

So the statement "Ethereal contains no Stockfish code" would be stronger than the evidence supports. The more accurate statement is:

Ethereal is an independently developed engine overall, but it has incorporated some code and many implementation techniques from other open-source engines, including Stockfish, under the GPL."

Can you give an example of code directly copied from Stockfish or any other engine?

ChatGPT: "Yes. One clear example is Syzygy tablebase probing.

Ethereal's syzygy.c is not an original implementation—it wraps Pyrrhic, which is itself a fork of Fathom, Ronald de Man's GPL Syzygy probing library that originated from the Stockfish ecosystem. Ethereal explicitly includes and interfaces with Pyrrhic rather than reimplementing the probing logic from scratch.

Another example, according to Andrew Grant himself, is:

Windows NUMA support, which he says was taken from Texel/Brainfish. He also states that, aside from Pyrrhic and this NUMA code, Ethereal does not explicitly use external source code.

So, if you're looking for direct code reuse rather than just ideas:

Syzygy probing (via the Pyrrhic/Fathom codebase).
Windows NUMA code (from Texel/Brainfish).

For Stockfish search code specifically, there isn't a publicly acknowledged example of a file that is simply copied wholesale. Most of the Stockfish influence there is in algorithms and heuristics rather than verbatim source code."

I'm sure many here would be interested your 'spin' on the facts above , as well as you dubious and confusing take on licenses...of course we all know you're a licensing genius! no disprespect intended!

[AndrewGrant]

I'm a bit curious as to why you have only responded to "Ethereal's syzygy.c is not an original implementation"

I started here, because it was easy to refute, as ChatGPT had made a mistake in the license.

Do you acknowledge that ChatGPT was mistaken to suggest the Pyrrhic/Fathom are under GPLv3?
And do you acknowledge that Ethereal is not violating anyone's copyright as it pertains to Pyrrhic/Fathom?

If you can acknowledge that, then we could start to discuss additional points of interest/concern.
But if we can't acknowledge this, then I don't see the point of trying to argue further. And we're also off-topic, and needing a new thread.

Edit:
Disappointing to see that you edited your post, to add a personal attack at the end. No reason for that.
The information I am conveying about licenses is something you could ask your LLM to explain as well.
I'm not offering novel legal takes here. This is all very textbook.

[Rebel]

Asked Claude a little more and it appears it already knows these conversations and that it is itself involved! You could regard the below as the response of Claude:

Yeah so I am not going to read that.

You can't stop the future Andy, it has been tried before and it did not work, better find a good compromise, as it happened before.

I don't think "the future" is me having to read AI generated content in a forum for humans. I suspect the conclusion you and Chris draw is that I am 100% anti AI, use non of the tools, and condone all use? Interesting estimation of my position if so, but not even remotely close.

If our most veteran members can't see the loss we'll suffer if humans delegate their interactions with others entirely to the AI, then we really are lost. If anything, you guys should hold my position. And I should be the young-naive one arguing for "progress".

I am old-school and a bit conservative, I did not enjoy the new course computer chess took after the first real strong open source engine Fruit-2.1 back in 2004 authors plundering its ideas. The fact I disliked the new course does not mean I have the right to condemn the new future ahead which gave an enormous elo jump and was legal also, clones were refused as best as the community was able.

Fast forward, anno 2026, I expressed my opinion a few years ago and still stick to it, the increased similarity between engines because on discord about everything is shared without competition which is a great compliment, but it comes with a price, a huge drop in originality. And I lost my interest in elo. Did I protest? No, the turn computer chess has taken is legal. I don't have to like progress.

And now we are into a new phase of computer chess, I don't like it, more loss in originality will come with it, Coda already shows a similarity of 58.9% to Stockfish 18, so there we go. For me the only question is if things are legal and if so I expect some programmers will also lose interest, very understandable.

You can delay things, maybe even stop the upcoming wave of new AI engines by collectively remove the source codes from GitHub.

[AndrewGrant]

I am old-school and a bit conservative, I did not enjoy the new course computer chess took after the first real strong open source engine Fruit-2.1 back in 2004 authors plundering its ideas. The fact I disliked the new course does not mean I have the right to condemn the new future ahead which gave an enormous elo jump and was legal also, clones were refused as best as the community was able.

Fast forward, anno 2026, I expressed my opinion a few years ago and still stick to it, the increased similarity between engines because on discord about everything is shared without competition which is a great compliment, but it comes with a price, a huge drop in originality. And I lost my interest in elo. Did I protest? No, the turn computer chess has taken is legal. I don't have to like progress.

And now we are into a new phase of computer chess, I don't like it, more loss in originality will come with it, Coda already shows a similarity of 58.9% to Stockfish 18, so there we go. For me the only question is if things are legal and if so I expect some programmers will also lose interest, very understandable.

You can delay things, maybe even stop the upcoming wave of new AI engines by collectively remove the source codes from GitHub.

It is possible to push back on things, and gain ground. The war against Leelers has been very successful. Between them being banned from CCC in general, and being treated as 2nd class entries to TCEC, people have largely taken up generating their own data, which is an avenue that allows for experimentation. Not least of which is that the training of an NNUE wildly differs based on the data source.

But I don't disagree with your sentiments, other than that I do protest. I saw in advance that NNUE was going to crush originality, and it largely did. Sometimes in ways I never expected, like sharing the same training data. Of course, it does give life to some new dimensions for people to innovate on. It is not all bad.

Personally, I don't see the draw to working on open-source anymore. The sort of joint, liberal minded effort where we all work together to build something, has met the brutal reality of unchecked capitalistic greed ( USA tech ), and unrivaled authoritarian reaches ( China, and USA soon ). It used to be the case that many of the people doing open-source dev, were also well-off, employed by these fancy tech companies pulling down great salaries... Well as everyone starts getting fired, and out sourced, that spare time and spare energy is going to collapse.

For me the only question is if things are legal

It is all quite plainly illegal ( and immoral, the more important part), but that does not matter. In due time, Anthropic, or SpaceX, or Google, will land more and more of these IP lawsuits into favorable courts, and change the interpretation of the law that way. If that is not enough, well it is not that expensive to get legislation written for your interests, especially if you're riding the trillion dollar AI boom.

[sscg13]

I am surprised this works, because past experiments have indicated to us that xray threats are very unlikely to be helpful.

It is suprisingly effective in Coda. About a month ago I did an ablation test. Taking a prod-like recipe model (at SB800, which is somewhat scaled down vs Coda prod) and trained with and without the xray features. Result here: https://ob.atwiss.com/test/2014/

This is interesting, but I would have also expected the inference code to change based on whether xray was included or removed, unless Coda does things differently.

-180 elo is also in the range where my first reaction would be to check for bugs.