One non-obvious reason is that an important aspect of their community is to shepherd new contributors [1]. LLMs crushing everything would reduce that. More obvious is all the toil for maintainers dealing with LLM PRs (broadly it’s an issue). The Zig maintainers prefer to put their energy into improving people and fostering those relationship.

[1] https://kristoff.it/blog/contributor-poker-and-ai/

There are other reasons why a project like Zig might not want to accept LLM generated contributions.

Zig, as programming language, has a multiplier codebase. A bug may affect a significant larger portion of users than most libraries or binaries will, as it's a fundamental building block of everything that uses Zig. Just that could be worth the extra scrutiny on every individual commit.

There's also the usual arguments: copyright ethics, environmental ethics and maintainer burden.

The LLM rule has been a thing for a very long time at this point.

>Makes me wonder why zig announced the strict LLM rule recently.

I guess there are 2 philosophies in software development: move fast and break things and move at a pace that guarantees everything is rock solid.

Most commercial software, Anthropic included is taking the former path, while most infrastructure teams are taking the later.

I guess Linux and FreeBSD kernels are also not accepting LLM based contributions yet.

Possibly, but the Zig creator is active on Lobste.rs, where he's been vocally anti-LLM for a year now, so the timing could just be a coincidence.

It's a combination of pragmatism (not wanting to wade through slop, not wanting to shove out newbie developers) and politics (usual contemporary techie progressive stuff that's now oddly anti-technology).