I am watching this project with interest.
It's impressive that they're doing such titanic work. However, I'm highly skeptical that they can create a real rival to established browsers. I'm sorry for telling this, but Web standards are simply too complex and huge. Ladybird to Chrome / Firefox is almost like Wine / ReactOS to Windows, that last 3-5% of gap actually differentiates a normal browser from a browser that is a pain for web developers. And it's the most stubborn part to be fixed. Also, keep in mind that it hasn't much market, at least IE had a significant market that forced the developers to support it (with all the hate).
https://waspdev.com/articles/2025-04-07/will-there-be-a-new-...
The history of Chrome and Safari traces back to KTML, the renderer for Konqueror, a niche browser on Linux with so little market share there weren't real conversations about it ever seriously competing with Firefox or IE.
Then something unexpected happened: Apple adopted KHTML for Safari's WebKit. WebKit was then adopted as the render for Chrome
Could a niche browser still become mainstream /today/? I think so.
Not even Firefox can keep up chasing down the chromium universe.
As of a week ago their pre-alpha version was capable of running my extremely heavy JS+ SVG + worker thread + SSE app, a bit slowly I admit but correctly in all major exercises I tried. So, I'm optimistic. They're doing great.
Separately I wonder if the compatibility job is easier now that you can just give the HTML5 spec to Fable and Bob's your uncle.