I've thought about this as well, especially for the case when it's a company owned product that is AGPLed. It's a really tough situation, because the last thing we want is competitors to come in and LLM wash our code to benefit their own product. I think this is a real risk.

On the other side, I deeply believe in the values of free software. My general stance is that all applications I open source are GPL or AGPL, and any libraries I open source are MIT. For the libraries, obviously anyone is free to use them, and if they want to rewrite them with an LLM more power to them. For the applications though, I see that as a violation of the license.

At the end of the day, I have competing values and needs and have to make a choice. The choice I've made for now is that for the vast majority of things, I'm still open sourcing them. The gift to humanity and the guarantee to the users freedom is more important to me than a theoretical threat. The one exception is anything that is truly a risk of getting lifted and used directly by competitors. I have not figured out an answer to this one yet, so for now I'm keeping it AGPL but not publicly distributing the code. I obviously still make the full code available to customers, and at least for now I've decided to trust my customers.

I think this is an issue we have to take week by week. I don't want to let fear of things cause us to make suboptimal decisions now. When there's an actual event that causes a reevaluation, I'll go from there.

Maybe we should requiring training data be published or at least referenced.

> Should I keep open sourcing my code now that the licence doesn't matter anymore?

your LICENSE matters in similar ways that it mattered before LLMs. LICENSE adherence is part of intellectual property law and practice. A popular engine may be popular, but not all cases at all times. Do not despair!

To my understanding, if the material is publicly available or obtained legally (i.e., not pirated), then training a model with it falls under fair use.

Once training is established as fair use, it doesn't really matter if the license is MIT, GPL, or a proprietary one.

And the current norm that the trillion dollar companies have lobbied for is that you can train on copyrighted material all you want so that's the reality we are living in. Everything ever published is all theirs.

A GPL license is a contract in most other countries. Just not US probably.

It's not specific to open source but it's most clearly enforceable with open source as there will be many contributors from many jurisdictions with the one unifying factor being they all made their copyright available under the same license terms.

With proprietary or more importantly single-owner code, it's far easier for this to end up in a settlement rather than being drug out into an actual ruling, enforcement action, and establishment of precedence.

That's the key detail. It's not specific to GPL or open source but if you want to see these orgs held to account and some precedence established, focusing on GPL and FOSS licensed code is the clearest path to that.

Ideally, Congress would just settle this basket of copyright concerns, as they explicitly have the power to do—and have done so repeatedly in the specific context of computers and software.

Anyone can very easily avoid training on GPL code. Yes, the model might be not be as strong as one that is trained that way and released under terms of the GPL, but to me that sounds like quite a good outcome if the best models are open source/open weight.

Its all about whose outcomes are optimized.

Of course, the law generally favors consideration of the outcomes for the massive corporations donating hundreds of millions of dollars to legislature campaigns.

To my understanding, if the material is publicly available or obtained legally (i.e., not pirated), then training a model with it falls under fair use, at least in the US and some other jurisdictions.

If the training is established as fair use, the underlying license doesn't really matter. The term you added would likely be void or deemed unenforceable if someone ever brought it to a court.

By that logic, humans would also be prevented from “training” on (i.e. learning from) such code. Hard to see how this could be a valid license.

Wouldn't it be still legal to train on the data due to fair use?

Would such a license fall under the definition of free software? Difficult to say. Counter-proposition: a license which permits training if the model is fully open.

We need a ruling that LLM generated code enters public domain automatically and can't be covered by any license.

A program's output is likely not owned by the program's authors. For example, if you create a document with Microsoft Word, you are the one who owns it, not Microsoft.

If you were a thoughtful, careful, law-abiding business, yes.

I submit the evidence suggests the genAI companies have none of those attributes.

Not crazy - there's a rational self-interest in doing this.

But I'm not certain that the relevant players have the same consequence-fearing mindset that you do, and to be honest they're probably right. The theft is too great to calculate the consequences, and by the time it's settled, what are you gonna do - turn off Forster's machine?

I hope you're right in at least some cases!

> I might be crazy, and I'd love to hear from somebody who knows about this, but I've been assuming that AI companies have been pulling GPL code out of the training material specifically to avoid this.

Haha no.

https://windsurf.com/blog/copilot-trains-on-gpl-codeium-does...

And just in the last two days, AI generating LGPL headers (which it could not do if identifying LGPL code was pulled from the codebase) and misattributing authors:

https://devclass.com/2025/11/27/ocaml-maintainers-reject-mas...

I had a very similar view once, and have since understood that this is mainly a difference in perspective:

It's easy as a developer to slip into a role where you want to build/package (maybe sell) some software product with minimal obligations. BSD-likes are obviously great there.

But the GPL follows a different perspective: It tries to make sure that every user of any software product is always capable of tinkering and changing it himself, and the more permissive licenses do not help there because they don't prevent (or even discourage!) companies from just selling you stripped and obfuscated binary blobs that put you fully at the vendors mercy.

It's not dictating how you use what you build? It's dictating how you redistribute what you build on top of other people's work.

I disagree as someone who has also spent a huge amount of time on open source software. It’s all GPL or AGPL :)

As somebody who thinks that people currently own the code that they write, I wonder why you're in people's business who want to write GPL'd software.

Are you complaining about proprietary software? I hear the restrictions are a lot tighter for Photoshop's source code, or iOS's, but for some reason you are one of the people who hate GPL as a hobby. Please don't show up whining about "spirits" when Amazon puts you out of business.

Try changing the system prompt or switch to opencode [0] - they allegedly reverse engineered Claude Code, and so the performance you get with Claude models should be very similar to Claude Code.

[0] https://github.com/sst/opencode

"Information wants to be free"? Many individuals pirated movies and games and got away with it. Of course two wrongs don't make a right and all that. Nonetheless one should be compensated for creating material that ai trained on for the same reasons copyright is compensated - to incentives people to produce it.

With an attitude like that they don't

The GPL was tested in court as early as 2006 [1] and plenty of times since. There are no serious doubts about its enforceability.

[1] https://www.fsf.org/news/wallace-vs-fsf

There have been a number of of cases, which are linked from Wikipedia (https://en.wikipedia.org/wiki/GNU_General_Public_License#Leg...) - most recently Entr’Ouvert v. Orange had a strong judgement (under French law) in favour of the GPL.

Conversely, to my knowledge there has been no court decision that indicates that the GPL is _not_ enforceable. I think you might want to be more familiar with the area before you decide if it's legally questionable or not.

If you don't like the license, then don't accept it.

You are then restricted by copyright just like with any other creation.

If I include the source code of Windows into my product, I can't simply choose to re-license it to say public domain and give it to someone else, the license that I have from Microsoft to allow me to use their code won't let me - it provides restrictions. It's just as "viral" as the GPL.