libjs-test262 VS Servo

Linus Groh of LibJS is an Invited Expert in TC39: https://linus.dev/posts/road-to-working-on-serenityos-and-la...

ECMAScript conformance test results looking good, 87-88% passing at the moment: https://libjs.dev/test262/

this is a qt frontend (definitely works on linux) for the serenityos browser engine, libweb.

this is a new, from-scratch implementation of both a modern html/css layout engine and a javascript runtime.

see https://libjs.dev/test262/ for ecmascript conformance tests.

the browser engine is far from finished but is able to display moderately complex pages like github.

it's always exciting to see a completely new web engine running in conventional environments like linux!

> Our JavaScript engine is decently mature, test262 score tracked here: https://libjs.dev/test262/

In a few years when they have achieved feature parity with Chromium or at least Safari we can discuss this again, but for now it's not ready for real life use.

See https://github.com/linusg/libjs-test262 for an example, specifically the CMake files and `src/main.cpp`.

The separate website is just to have a nice & short link to the test262 graph and whatever else we'll put there eventually; and also because it's built/deployed in a slightly different way than the main serenityos.org website.

> Is there any easy to use/hack HTML layouting engine where I could experiment with custom CSS attributes and bridge that gap? Would anything from Servo be suitable?

Servo could be used for this. You'd want to add support for parsing the CSS properties themselves to the style crate in https://github.com/servo/stylo and then the layout implementation to the layout2020 crate in https://github.com/servo/servo. You do effectively get a whole browser though.

I'm currently working on building a lighter weight / hackable layout engine based on a combination of https://github.com/servo/stylo (for css parsing and selector resolution), https://github.com/DioxusLabs/taffy (for box-level layout) and https://github.com/pop-os/cosmic-text (for flow/inline layout). I expect to have something decent in around 6 months

Neither of these setups currently have any support for pagination though.

Great to see some competition still alive in browser engine development. See also Servo (previously part of Mozilla) https://servo.org/ - that and Ladybird are still very underdeveloped compared to every day browsers.

It's a huge shame that there are no nightly builds of ladybird to try out but I assume that's because they just don't want the bug reports (if everything doesn't work it's pointless getting random bugs filed).

I haven't messed with it yet but from looking into it, this should absolutely work.

https://github.com/servo/servo/wiki/Building-on-ARM-desktop-...

don't know, there was a downtime in 2021 and 22 but since 2023, contributions look back to where it was before .. https://github.com/servo/servo/graphs/contributors

The world has moved on though to opinionated tools, and Rust isn't even the furthest in that direction (That would be Go). The equivalent of those two lines in Cargo.toml would be this example of a basic configuration from the jacoco-maven-plugin: https://www.jacoco.org/jacoco/trunk/doc/examples/build/pom.x... - That's 40 lines in the section to do the "defaults".

Yes, you could add a load of config for files to include/exclude from coverage and so on, but the idea that that's a norm is way more common in Java projects than other languages. Like here's some example Cargo.toml files from complicated Rust projects:

Servo: https://github.com/servo/servo/blob/main/Cargo.toml

rust-gdext: https://github.com/godot-rust/gdext/blob/master/godot-core/C...

ripgrep: https://github.com/BurntSushi/ripgrep/blob/master/Cargo.toml

socketio: https://github.com/1c3t3a/rust-socketio/blob/main/socketio/C...

1. Servo

It won't don't worry. There already are forks, for the worst case scenario. And Servo is on its way. Not yet ready, but it will be. Originally, from Mozilla kitchen.

To pain broad strokes, the layout phase (~= take the HTML, take the CSS, determine the position and size of boxes) is largely sequential in production browser engine today. Selector matching (~= what CSS applies to what element) is parallel in Firefox today, via the Stylo Rust crate originally developed in the research browser engine Servo. Servo can do parallel layout in some capacity (but doesn't implement everything), https://github.com/servo/servo/wiki/Servo-Layout-Engines-Rep... is an interesting and recent document on the matter.

Parallel layout is generally considered to be a complex engineering problem by domain experts.

https://hacks.mozilla.org/2017/08/inside-a-super-fast-css-en... is a really cool article that is related, that is a few years old but what it says is largely correct today.

[Article author/submitter here]

I can only tell you that it is not what this is about, inasmuch as I was at the talk and there was not a single mention of Firefox Reality or Wolvic in the talk.

Wolvic might use Servo – but I think if it did they would mention it, right?

The talk didn't and the word "Wolvic" does not occur anywhere on https://servo.org

So I am guessing not, no.

Igalia has -- or rather is because it's a co-op -- about 100 developers. They are not all working on the same thing.