7 ms·

The comment that points out that this week-long experiment produced nothing more than a non-functional wrapper for Servo (an existing Rust browser) should be at

by pavlov 9mo ago

The comment that points out that this week-long experiment produced nothing more than a non-functional wrapper for Servo (an existing Rust browser) should be at the top: https://news.ycombinator.com/item?id=46649046 https://news.ycombinator.com/item?id=46649046

pera 9mo ago
Has anyone tried to rewrite some popular open source project with IA? I imagine modern LLMs can be very effective at license-washing/plagiarizing dependencies, it could be an interesting new benchmark too
- benhoyt 9mo ago
  Not me personally, but a GitHub user wrote a replacement for Go's regexp library that was "up to 3-3000x+ faster than stdlib": https://github.com/coregx/coregex https://github.com/coregx/coregex ... at first I was impressed, so started testing it and reporting bugs, but as soon as I ran my own benchmarks, it all fell apart (https://github.com/coregx/coregex/issues/29 https://github.com/coregx/coregex/issues/29). After some mostly-bot updates, that issue was closed. But someone else opened a very similar one recently (https://github.com/coregx/coregex/issues/79 https://github.com/coregx/coregex/issues/79) -- same deal, "actually, it's slower than the stdlib in my tests". Basically AI slop with poor tests, poor benchmarks, and way oversold. How he's positioning these projects is the problematic bit, I reckon, not the use of AI. Same user did a similar thing by creating an AWK interpreter written in Go using LLMs: https://github.com/kolkov/uawk https://github.com/kolkov/uawk -- as the creator of (I think?) the only AWK interpreter written in Go (https://github.com/benhoyt/goawk https://github.com/benhoyt/goawk), I was curious. It turns out that if there's only one item in the training data (GoAWK), AI likes to copy and paste freely from the original. But again, it's poorly tested and poorly benchmarked. I just don't see how one can get quality like this, without being realistic about code review, testing, and benchmarking.
  - CuriouslyC 9mo ago
    To be fair, good benchmarking is hard, most people get it wrong. Scientific training helps.
  - dragonwriter 9mo ago
    > up to 3-3000x+ faster than stdlib Note that this is semantically exactly equivalent to "up to 3000x faster than stdlib" and doesn't actually claim any particular actual speedup since "up to" denotes an upper bound, not a lower bound or expected value. It’s standard misleading-but-not-technically-false marketing language to create a false impression because people tend to focus on the number and ignore the "up to".
    - supriyo-biswas 9mo ago
      Reminds me of https://xkcd.com/870/ https://xkcd.com/870/
    - arcticbull 9mo ago
      With the “up to 3-3000x+” language the plus leaves us with the entire number line.
    - Dylan16807 9mo ago
      When you say "up to" about a list of data points, it's not just a bound. At least one has to reach that amount or it's a lie.
    - nkrisc 9mo ago
      Saying “up to” means that bound is the maximum value of the data set. It may be far from the median value, but it is included (or you’re lying). With any other interpretation the phrase has no meaning whatsoever.
      - nkrisc 9mo ago
        I will concede, proactively, that "up to" could refer to some maximum possible bound, even if the current set doesn't include a value at that bound, though I would argue that's likely deceptive wording. For example, you could say that each carton of of eggs on a pallet contains up to 12 eggs, because that's the maximum capacity of the carton, even if none of the actual cartons on this pallet actually have 12 eggs in them.
- gorkaerana 9mo ago
  I think it's fair enough to consider porting a subset of rewriting, in which case there are several successful experiments out there: - JustHTML [1], which in practice [2] is a port of html5ever [3] to Python. - justjshtml, which is a port of JustHTML to JavaScript :D [4]. - MiniJinja [5] was recently ported to Go [6]. All three projects have one thing in common: comprehensive test suites which were used to guardrail and guide AI. References: 1. https://github.com/EmilStenstrom/justhtml https://github.com/EmilStenstrom/justhtml 2. https://friendlybit.com/python/writing-justhtml-with-coding-agents/ https://friendlybit.com/python/writing-justhtml-with-coding-... 3. https://github.com/servo/html5ever https://github.com/servo/html5ever 4. https://simonwillison.net/2025/Dec/15/porting-justhtml/ https://simonwillison.net/2025/Dec/15/porting-justhtml/ 5. https://github.com/mitsuhiko/minijinja https://github.com/mitsuhiko/minijinja 6. https://lucumr.pocoo.org/2026/1/14/minijinja-go-port/ https://lucumr.pocoo.org/2026/1/14/minijinja-go-port/
  - daxfohl 9mo ago
    Interesting, IIUC the transformer architecture / attention mechanism were initially designed for use in the language translation domain. Maybe after peeling back a few layers, that's still all they're really doing.
    - nathan_compton 9mo ago
      This has long been how I have explained LLMs to non-technical people: text transformation engines. To some extent, many common, tedious, activities basically constitute a transformation of text into one well known form from another (even some kinds of reasoning are this) and so LLMs are very useful. But they just transform text between well known forms.
      - daxfohl 9mo ago
        And while it appears that lots of problems can be contorted into translation, "if all you have is a hammer, everything looks like a nail". Maybe we do hit a brick wall unless we can come up with a model that more closely aligns with actual human reasoning.
- deleted 9mo ago
  [deleted]
- hedgehog 9mo ago
  I used one of the assistants to reverse and rewrite a browser-hosted JS game-like app to desktop Rust. It required a lot of steering but it was pretty useful.
quotemstr 9mo ago
Negative results are great. When you publish them on purpose, it's honorable. When you reveal them by accidentally, it's hilarious. Cheers to Cursor for today's entertainment.
gjsman-1000 9mo ago
What the hell? I was seeing screenshots and actually getting scared for my job for a second. It’s broken and there’s no browser engine? Cursor should be tarred and feathered.
- autoexec 9mo ago
  A lie like this seems like it should be considered fraud
  - thrwaway55 9mo ago
    FSD next year! Our safeguards are a joke so it's not surprising to see this behavior
AstroBen 9mo ago
Apparebtly this person actually got it to compile: https://xcancel.com/CanadaHonk/status/2011612084719796272#m https://xcancel.com/CanadaHonk/status/2011612084719796272#m
- observationist 9mo ago
  https://x.com/CanadaHonk/status/2011612084719796272 https://x.com/CanadaHonk/status/2011612084719796272 as well. I went through the motions. There are various points in the repo history where compilation is possible, but it's obscure. They got it to compile and operate prior to the article, but several of the PRs since that point broke everything, and this guy went through the effort of fixing it. I'm pretty sure you can just identify the last working commit and pull the version from there, but working out when looks like a big pain in the butt for a proof of concept.
  - embedding-shape 9mo ago
    > but several of the PRs since that point broke everything, and this guy went through the effort of fixing it. I'm pretty sure you can just identify the last working commit and pull the version from there, but working out when looks like a big pain in the butt for a proof of concept. I went through the last 100 commits (https://news.ycombinator.com/item?id=46647037 https://news.ycombinator.com/item?id=46647037) and nothing there was working (yet/since). Seems now after a developer corrected something it managed to pass `cargo check` without errors, since commit 526e0846151b47cc9f4fcedcc1aeee3cca5792c1 (Jan 16 02:15:02 2026 -0800)
    - observationist 9mo ago
      There are conversations elsewhere - I'd have to go look through them, but at some point about an hour before the article was published, it could be compiled, and then things got pushed that broke it again? There's no central discussion, I had to piece together information from multiple threads. Sorry, I should have taken notes, lol. At any rate, it was so much digging around I just gave up, I didn't want to invest more effort into it. I figured they'd get a stable version for others to try and I'd return to it at some point.
mvdtnz 9mo ago
Why is the top comment on this item just a link to another comment on this same story?
- deleted 9mo ago
  [deleted]
M4v3R 9mo ago
It’s not just a wrapper for Servo, the linked poster just checked the dependencies in the Cargo file and proclaimed that without checking anything further. In reality this project does indeed implement a functioning custom JS Engine, Layout engine, painting etc. It does borrow the CSS selectors package from Servo but that’s about it.
- oefrha 9mo ago
  Yeah there's more to a browser than a couple of out-of-tree servo components, otherwise https://github.com/servo/servo https://github.com/servo/servo wouldn't have 300k+ lines of Rust code, 400k+ if you count comments and blanks (I cloned the repo, nuked the tests directory, then did a count). Plus that linked comment doesn't even say it's "nothing more than a non-functional wrapper for Servo". It disputes the "from scratch" claim. Most people aren't interested in a nuanced take though. Someone said something plausible sounding and was voted to top by other people? Good enough for me, have another vote. Then twist and exaggerate a little and post it to another comment section. Get more votes. Rinse and repeat.
- pera 9mo ago
  "Borrow" is an interesting choice of word, see for example this: /// The quirks mode of the document. #[inline] pub fn quirks_mode(&self) -> QuirksMode { self.quirks_mode } https://github.com/wilsonzlin/fastrender/blob/3e5bc78b075645fc04635336fbde6e005a6f1b5f/vendor/selectors/context.rs#L328 https://github.com/wilsonzlin/fastrender/blob/3e5bc78b075645... And then this: /// The quirks mode of the document. pub fn quirks_mode(&self) -> QuirksMode { self.stylist.quirks_mode() } https://github.com/servo/stylo/blob/71737ad5c8b29c143a6c992af6222833f5d38b43/style/context.rs#L170 https://github.com/servo/stylo/blob/71737ad5c8b29c143a6c992a... It seems ChatGPT is still copying segments of code almost verbatim, although sometimes it does weird things, compare these for example: https://github.com/wilsonzlin/fastrender/blob/3e5bc78b075645fc04635336fbde6e005a6f1b5f/vendor/selectors/parser.rs#L68 https://github.com/wilsonzlin/fastrender/blob/3e5bc78b075645... https://github.com/servo/stylo/blob/71737ad5c8b29c143a6c992af6222833f5d38b43/style/gecko/pseudo_element.rs#L356 https://github.com/servo/stylo/blob/71737ad5c8b29c143a6c992a...
wilsonzlin 9mo ago
I've responded to this claim in more detail at [0], with additional context at [1]. Briefly, the project implemented substantial components, including a JS VM, DOM, CSS cascade, inline/block/table layout, paint systems, text pipeline, and chrome, and is not merely a Servo wrapper. [0] https://news.ycombinator.com/item?id=46650998 https://news.ycombinator.com/item?id=46650998 [1] https://news.ycombinator.com/item?id=46655608 https://news.ycombinator.com/item?id=46655608
- embedding-shape 9mo ago
  Could you somewhere make clear exactly how much of the code was "autonomously" built vs how much was steered by humans? Because at this point it's clear that it wasn't 100% autonomous as originally claimed, but right now it's not clear if this was just the work of an engineer running Cursor vs "autonomously organised a fleet of agents".
- pera 9mo ago
  Just for context, this was the original claim by Cursor's CEO on Twitter: > We built a browser with GPT-5.2 in Cursor. It ran uninterrupted for one week. > It's 3M+ lines of code across thousands of files. The rendering engine is from-scratch in Rust with HTML parsing, CSS cascade, layout, text shaping, paint, and a custom JS VM. > It kind of works! It still has issues and is of course very far from Webkit/Chromium parity, but we were astonished that simple websites render quickly and largely correctly. https://xcancel.com/mntruell/status/2011562190286045552#m https://xcancel.com/mntruell/status/2011562190286045552#m
- delusional 9mo ago
  I cannot make these two statements true at the same time in my head: > Briefly, the project implemented substantial components, including a JS VM and from the linked reply: > vendor/ecma-rs as part of the browser, which is a copy of my personal JS parser project vendored to make it easier to commit to. If it's using a copy of your personal JS parser that you decided it should use, then it didn't implement it "autonomously". The references you're linking don't summarize to the brief you've provided. What the fuck is going on?
deleted 9mo ago
[deleted]
holoduke 9mo ago
A bit off topic, but fun for people having lots of Claude credits. Auto Claude is a nice opensource repo to let Claude generate entire application from just one prompt. Lots of Jolo vibing her, but nevertheless impressive. Last week I asked it in one sentence to create a full blown Hotel website including all the software tools for backoffice. It took almost 4 days with 4 Claude accounts. It actually created a working thing.

by pavlov 9mo ago

pera 9mo ago

Has anyone tried to rewrite some popular open source project with IA? I imagine modern LLMs can be very effective at license-washing/plagiarizing dependencies, it could be an interesting new benchmark too

benhoyt 9mo ago
Not me personally, but a GitHub user wrote a replacement for Go's regexp library that was "up to 3-3000x+ faster than stdlib": https://github.com/coregx/coregex https://github.com/coregx/coregex ... at first I was impressed, so started testing it and reporting bugs, but as soon as I ran my own benchmarks, it all fell apart (https://github.com/coregx/coregex/issues/29 https://github.com/coregx/coregex/issues/29). After some mostly-bot updates, that issue was closed. But someone else opened a very similar one recently (https://github.com/coregx/coregex/issues/79 https://github.com/coregx/coregex/issues/79) -- same deal, "actually, it's slower than the stdlib in my tests". Basically AI slop with poor tests, poor benchmarks, and way oversold. How he's positioning these projects is the problematic bit, I reckon, not the use of AI. Same user did a similar thing by creating an AWK interpreter written in Go using LLMs: https://github.com/kolkov/uawk https://github.com/kolkov/uawk -- as the creator of (I think?) the only AWK interpreter written in Go (https://github.com/benhoyt/goawk https://github.com/benhoyt/goawk), I was curious. It turns out that if there's only one item in the training data (GoAWK), AI likes to copy and paste freely from the original. But again, it's poorly tested and poorly benchmarked. I just don't see how one can get quality like this, without being realistic about code review, testing, and benchmarking.
- CuriouslyC 9mo ago
  To be fair, good benchmarking is hard, most people get it wrong. Scientific training helps.
- dragonwriter 9mo ago
  > up to 3-3000x+ faster than stdlib Note that this is semantically exactly equivalent to "up to 3000x faster than stdlib" and doesn't actually claim any particular actual speedup since "up to" denotes an upper bound, not a lower bound or expected value. It’s standard misleading-but-not-technically-false marketing language to create a false impression because people tend to focus on the number and ignore the "up to".
  - supriyo-biswas 9mo ago
    Reminds me of https://xkcd.com/870/ https://xkcd.com/870/
  - arcticbull 9mo ago
    With the “up to 3-3000x+” language the plus leaves us with the entire number line.
  - Dylan16807 9mo ago
    When you say "up to" about a list of data points, it's not just a bound. At least one has to reach that amount or it's a lie.
  - nkrisc 9mo ago
    Saying “up to” means that bound is the maximum value of the data set. It may be far from the median value, but it is included (or you’re lying). With any other interpretation the phrase has no meaning whatsoever.
    - nkrisc 9mo ago
      I will concede, proactively, that "up to" could refer to some maximum possible bound, even if the current set doesn't include a value at that bound, though I would argue that's likely deceptive wording. For example, you could say that each carton of of eggs on a pallet contains up to 12 eggs, because that's the maximum capacity of the carton, even if none of the actual cartons on this pallet actually have 12 eggs in them.
gorkaerana 9mo ago
I think it's fair enough to consider porting a subset of rewriting, in which case there are several successful experiments out there: - JustHTML [1], which in practice [2] is a port of html5ever [3] to Python. - justjshtml, which is a port of JustHTML to JavaScript :D [4]. - MiniJinja [5] was recently ported to Go [6]. All three projects have one thing in common: comprehensive test suites which were used to guardrail and guide AI. References: 1. https://github.com/EmilStenstrom/justhtml https://github.com/EmilStenstrom/justhtml 2. https://friendlybit.com/python/writing-justhtml-with-coding-agents/ https://friendlybit.com/python/writing-justhtml-with-coding-... 3. https://github.com/servo/html5ever https://github.com/servo/html5ever 4. https://simonwillison.net/2025/Dec/15/porting-justhtml/ https://simonwillison.net/2025/Dec/15/porting-justhtml/ 5. https://github.com/mitsuhiko/minijinja https://github.com/mitsuhiko/minijinja 6. https://lucumr.pocoo.org/2026/1/14/minijinja-go-port/ https://lucumr.pocoo.org/2026/1/14/minijinja-go-port/
- daxfohl 9mo ago
  Interesting, IIUC the transformer architecture / attention mechanism were initially designed for use in the language translation domain. Maybe after peeling back a few layers, that's still all they're really doing.
  - nathan_compton 9mo ago
    This has long been how I have explained LLMs to non-technical people: text transformation engines. To some extent, many common, tedious, activities basically constitute a transformation of text into one well known form from another (even some kinds of reasoning are this) and so LLMs are very useful. But they just transform text between well known forms.
    - daxfohl 9mo ago
      And while it appears that lots of problems can be contorted into translation, "if all you have is a hammer, everything looks like a nail". Maybe we do hit a brick wall unless we can come up with a model that more closely aligns with actual human reasoning.
deleted 9mo ago
[deleted]
hedgehog 9mo ago
I used one of the assistants to reverse and rewrite a browser-hosted JS game-like app to desktop Rust. It required a lot of steering but it was pretty useful.

quotemstr 9mo ago

Negative results are great. When you publish them on purpose, it's honorable. When you reveal them by accidentally, it's hilarious. Cheers to Cursor for today's entertainment.

gjsman-1000 9mo ago

What the hell? I was seeing screenshots and actually getting scared for my job for a second. It’s broken and there’s no browser engine? Cursor should be tarred and feathered.

autoexec 9mo ago
A lie like this seems like it should be considered fraud
- thrwaway55 9mo ago
  FSD next year! Our safeguards are a joke so it's not surprising to see this behavior

AstroBen 9mo ago

Apparebtly this person actually got it to compile: https://xcancel.com/CanadaHonk/status/2011612084719796272#m https://xcancel.com/CanadaHonk/status/2011612084719796272#m

observationist 9mo ago
https://x.com/CanadaHonk/status/2011612084719796272 https://x.com/CanadaHonk/status/2011612084719796272 as well. I went through the motions. There are various points in the repo history where compilation is possible, but it's obscure. They got it to compile and operate prior to the article, but several of the PRs since that point broke everything, and this guy went through the effort of fixing it. I'm pretty sure you can just identify the last working commit and pull the version from there, but working out when looks like a big pain in the butt for a proof of concept.
- embedding-shape 9mo ago
  > but several of the PRs since that point broke everything, and this guy went through the effort of fixing it. I'm pretty sure you can just identify the last working commit and pull the version from there, but working out when looks like a big pain in the butt for a proof of concept. I went through the last 100 commits (https://news.ycombinator.com/item?id=46647037 https://news.ycombinator.com/item?id=46647037) and nothing there was working (yet/since). Seems now after a developer corrected something it managed to pass `cargo check` without errors, since commit 526e0846151b47cc9f4fcedcc1aeee3cca5792c1 (Jan 16 02:15:02 2026 -0800)
  - observationist 9mo ago
    There are conversations elsewhere - I'd have to go look through them, but at some point about an hour before the article was published, it could be compiled, and then things got pushed that broke it again? There's no central discussion, I had to piece together information from multiple threads. Sorry, I should have taken notes, lol. At any rate, it was so much digging around I just gave up, I didn't want to invest more effort into it. I figured they'd get a stable version for others to try and I'd return to it at some point.

mvdtnz 9mo ago

Why is the top comment on this item just a link to another comment on this same story?

deleted 9mo ago
[deleted]

M4v3R 9mo ago

It’s not just a wrapper for Servo, the linked poster just checked the dependencies in the Cargo file and proclaimed that without checking anything further. In reality this project does indeed implement a functioning custom JS Engine, Layout engine, painting etc. It does borrow the CSS selectors package from Servo but that’s about it.

oefrha 9mo ago
Yeah there's more to a browser than a couple of out-of-tree servo components, otherwise https://github.com/servo/servo https://github.com/servo/servo wouldn't have 300k+ lines of Rust code, 400k+ if you count comments and blanks (I cloned the repo, nuked the tests directory, then did a count). Plus that linked comment doesn't even say it's "nothing more than a non-functional wrapper for Servo". It disputes the "from scratch" claim. Most people aren't interested in a nuanced take though. Someone said something plausible sounding and was voted to top by other people? Good enough for me, have another vote. Then twist and exaggerate a little and post it to another comment section. Get more votes. Rinse and repeat.
pera 9mo ago
"Borrow" is an interesting choice of word, see for example this: /// The quirks mode of the document. #[inline] pub fn quirks_mode(&self) -> QuirksMode { self.quirks_mode } https://github.com/wilsonzlin/fastrender/blob/3e5bc78b075645fc04635336fbde6e005a6f1b5f/vendor/selectors/context.rs#L328 https://github.com/wilsonzlin/fastrender/blob/3e5bc78b075645... And then this: /// The quirks mode of the document. pub fn quirks_mode(&self) -> QuirksMode { self.stylist.quirks_mode() } https://github.com/servo/stylo/blob/71737ad5c8b29c143a6c992af6222833f5d38b43/style/context.rs#L170 https://github.com/servo/stylo/blob/71737ad5c8b29c143a6c992a... It seems ChatGPT is still copying segments of code almost verbatim, although sometimes it does weird things, compare these for example: https://github.com/wilsonzlin/fastrender/blob/3e5bc78b075645fc04635336fbde6e005a6f1b5f/vendor/selectors/parser.rs#L68 https://github.com/wilsonzlin/fastrender/blob/3e5bc78b075645... https://github.com/servo/stylo/blob/71737ad5c8b29c143a6c992af6222833f5d38b43/style/gecko/pseudo_element.rs#L356 https://github.com/servo/stylo/blob/71737ad5c8b29c143a6c992a...

wilsonzlin 9mo ago

I've responded to this claim in more detail at [0], with additional context at [1]. Briefly, the project implemented substantial components, including a JS VM, DOM, CSS cascade, inline/block/table layout, paint systems, text pipeline, and chrome, and is not merely a Servo wrapper. [0] https://news.ycombinator.com/item?id=46650998 https://news.ycombinator.com/item?id=46650998 [1] https://news.ycombinator.com/item?id=46655608 https://news.ycombinator.com/item?id=46655608

embedding-shape 9mo ago
Could you somewhere make clear exactly how much of the code was "autonomously" built vs how much was steered by humans? Because at this point it's clear that it wasn't 100% autonomous as originally claimed, but right now it's not clear if this was just the work of an engineer running Cursor vs "autonomously organised a fleet of agents".
pera 9mo ago
Just for context, this was the original claim by Cursor's CEO on Twitter: > We built a browser with GPT-5.2 in Cursor. It ran uninterrupted for one week. > It's 3M+ lines of code across thousands of files. The rendering engine is from-scratch in Rust with HTML parsing, CSS cascade, layout, text shaping, paint, and a custom JS VM. > It kind of works! It still has issues and is of course very far from Webkit/Chromium parity, but we were astonished that simple websites render quickly and largely correctly. https://xcancel.com/mntruell/status/2011562190286045552#m https://xcancel.com/mntruell/status/2011562190286045552#m
delusional 9mo ago
I cannot make these two statements true at the same time in my head: > Briefly, the project implemented substantial components, including a JS VM and from the linked reply: > vendor/ecma-rs as part of the browser, which is a copy of my personal JS parser project vendored to make it easier to commit to. If it's using a copy of your personal JS parser that you decided it should use, then it didn't implement it "autonomously". The references you're linking don't summarize to the brief you've provided. What the fuck is going on?

deleted 9mo ago

[deleted]

holoduke 9mo ago

A bit off topic, but fun for people having lots of Claude credits. Auto Claude is a nice opensource repo to let Claude generate entire application from just one prompt. Lots of Jolo vibing her, but nevertheless impressive. Last week I asked it in one sentence to create a full blown Hotel website including all the software tools for backoffice. It took almost 4 days with 4 Claude accounts. It actually created a working thing.