Ladybird adopts Rust, with help from AI (ladybird.org)

submitted 1 month ago by SwooshBakery624@programming.dev to c/opensource@lemmy.ml

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We’ve been searching for a memory-safe programming language to replace C++ in Ladybird for a while now. We previously explored Swift, but the C++ interop never quite got there, and platform support outside the Apple ecosystem was limited. Rust is a different story. The ecosystem is far more mature for systems programming, and many of our contributors already know the language. Going forward, we are rewriting parts of Ladybird in Rust.

Porting LibJS

I used Claude Code and Codex for the translation. This was human-directed, not autonomous code generation. I decided what to port, in what order, and what the Rust code should look like. It was hundreds of small prompts, steering the agents where things needed to go. After the initial translation, I ran multiple passes of adversarial review, asking different models to analyze the code for mistakes and bad patterns.

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[-] Solumbran@lemmy.world 92 points 1 month ago* (last edited 1 month ago)

"We want rust for safety. That's why we made the code in the most unreliable way to code known to humanity".

Not surprising from the devs that think that not being a fascist is political I guess

Edit : ah apparently the guy is not trying to be an enlightened centrist anymore and is a full-on nazi. Heh, who could have guessed? /s

[-] gravitas_deficiency@sh.itjust.works 22 points 1 month ago

Woah wait what? The “let’s vibecode it” angle is fucking stupid, to be clear, but I was unaware of that user drama. Very interesting.

[-] Solumbran@lemmy.world 31 points 1 month ago

It keeps on coming back and ladybird supporters keep on trying to tone it down because they don't want the project to die. But yeah, the guy seems like a big piece of shit.

[-] KryptonNerd@slrpnk.net 8 points 1 month ago

Got a source for that? I tried searching on DDG but couldn't find anything

[-] Solumbran@lemmy.world 26 points 1 month ago

https://drewdevault.com/2025/09/24/2025-09-24-Cloudflare-and-fascists.html

Here's one, you can find more stuff by searching the name of the dev

[-] hackerwacker@lemmy.ml 1 points 1 month ago

DeVault is an insidious troll and he seems to have some pretty deep mental problems. He doesn't deserve to be listened to. https://dmpwn.info/

[-] SwooshBakery624@programming.dev 7 points 1 month ago* (last edited 1 month ago)

I will copy my comment here:

Just so you know, Drew DeVault is a pedophile apologist. He cannot even remotely be considered a reliable source of information.

However, I completely agree regarding the use of AI, especially in a project such as a browser engine.

EDIT: I accidentally replied to this comment instead of the one with the link to Drew DeVault's blog. My bad.

[-] orc_princess@lemmy.ml 5 points 1 month ago* (last edited 1 month ago)

That is appalling, and I don't mean to diminish the importance of this, but if the claims on fascism stand to scrutiny then it's not relevant, and if the claims don't stand to scrutiny they can be easily refuted.

Edit: and to be clear, I know DHH, I've read his blog and his social media activity, he's clearly a fascist.

[-] UnspecificGravity@piefed.social 4 points 1 month ago

Most of the information that you get about terrible people comes from terrible people because that is who knows them. Should we discount Trump accusations from Epstein because they came from a known pedo? No, pedos are the people that Trump hangs out with because that is what he is.

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[-] WalrusDragonOnABike@reddthat.com 2 points 1 month ago

When they don't seem to know what definition the person is using for the word after writing an actual and seem confused why some of the quotes are against sexual abuse of 14 year olds, it's sorta hard to take their claims serious. IF DD's point is just people with the sexual preference deserve pity, then I agree. Just in the same way I think people with problems such as gambling or drug addictions should be pitied - it's not something they've chosen and it negatively effects their quality of life. Otoh, I don't think a gambling addict, for example, should be forgiven if they bankrupt their family and cause their children to grow up in poverty unnecessarily. Otoh, it it's a history of defending child abuse, then agreed there should be some discounting going on (but that seems the opposite of the quotes provided).

Either way, isn't the record for ladybird stuff in the git repo or something like that? Doesn't really matter what the source is that brought attention to it if you have the primary source (but people shouldn't be linking to problematic blogs - either link to the primary source or find/make another user-friendly secondary source).

[-] morto@piefed.social 50 points 1 month ago

We need competition in the browser market, ANY competition!

* ladybird appears *

Well... that was on me, I set the bar too low

[-] toastal@lemmy.ml 2 points 1 month ago

I mean when they adopted MS GitHub & Discord as their only modes of community & contribution, you can know any “open source” project is built on sand

[-] SwooshBakery624@programming.dev 48 points 1 month ago

I am completely disappointed in Ladybird, even though I had some hope for the project until now. I guess all that's left to do is wait for Servo.

[-] Midnitte@beehaw.org 15 points 1 month ago

Given that Servo was already written in rust (and not just some of it), it does feel a bit like wasted effort.

(Plus, it was started by Mozilla, so theres the irony factor)

[-] racketlauncher831@lemmy.ml 32 points 1 month ago

Your final hope at this point is announcing you will not use LLM to write any part of your program, including tests. Adopting a language which your developers are less familiar is bad enough, and you're writing it with LLM? I'd rather you stick with C++.

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[-] darkkite@lemmy.ml 10 points 1 month ago

The requirement from the start was byte-for-byte identical output from both pipelines. The result was about 25,000 lines of Rust, and the entire port took about two weeks. The same work would have taken me multiple months to do by hand. We’ve verified that every AST produced by the Rust parser is identical to the C++ one, and all bytecode generated by the Rust compiler is identical to the C++ compiler’s output. Zero regressions across the board:

Seems like a non-issue.