zlacker

>>embedd+(OP)
The CEO said

> 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.

"From scratch" sounds very impressive. "custom JS VM" is as well. So let's take a look at the dependencies [1], where we find

- html5ever

- cssparser

- rquickjs

That's just servo [2], a Rust based browser initially built by Mozilla (and now maintained by Igalia [3]) but with extra steps. So this supposed "from scratch" browser is just calling out to code written by humans. And after all that it doesn't even compile! It's just plain slop.

[1] - https://github.com/wilsonzlin/fastrender/blob/main/Cargo.tom...

[2] - https://github.com/servo/servo

[3] - https://blogs.igalia.com/mrego/servo-2025-stats/

>>nindal+BA
Is it using Servo's layout code or did Cursor write its own layout? That's one of the hardest parts.

>>wmf+Oo1
It's using layout code from my library (Taffy) for Flexbox and CSS Grid. Servo uses Taffy for CSS Grid, and another open source engine that I work on (Blitz) uses it for Flexbox, CSS Grid, Block and float layout.

The older block/inline layout modes seem to be custom code that looks to me similar but not exactly the same as Servo code. But I haven't compared this closely.

I would note that the AI does not seem to have matched either Servo or Blitz in terms of layout: both can layout Google.com better than the posted screenshot.