Early stages of Google Docs support in the Ladybird browser

Rust is very cool and have no issue with it in the kernel tree but C++ would prevent so many bugs and eliminate so many lines of code. It's just ego.

The DOM, etc through the work that eventually got labeled HTML5 made it possible to follow the spec and, as a super simple and "obvious" example, parse URLs in a way that worked. The existing specs of the era were often incomplete, semi-frequently what they did say did not match how browsers actually worked, and frequently ambiguous which meant that implementing anything required exhaustively testing what everyone else did to try and match it.

TC39 eventually recognized that the same issues existed in the ECMAScript spec, and recognized that ES4 did nothing to resolve those issues, while adding considerable complexity and more of the same issues. That's how we ended up with ES3.1 - it was an attempt to actually correctly and completely specify the language and runtime, ES5 continued/finished that catchup (ES3.1 did not resolve all the issues) while adding a few important features, but was still in the "make it possible for someone to implement the spec and be confident that they could run anything any other engine could run".

So in the modern browser there are many more specs, but those specs are much easier to confidently implement as you can get basic working behaviour by essentially translating the spec language into your environment.

Making the resulting engine fast, memory efficient, etc is of course another thing entirely (although even that is aided by removing ambiguity in the specs as the lack of ambiguity means that you can actually write tests now).

If it was written in Rust on the other hand, it eliminates those specific class of vulnerabilities.

At google’s size/cash implementing these things might be achievable, but I recall many people/projects over the years that decided to do in canvas rather than using the available engine (often times a belief that their desire for pixel perfect positions was reasonable, and more than made up for needing to draw everything and manage text entry themselves) always looks easy at first glance, typically because the authors don’t use accessibility tools and most who I interacted with were English-first devs who believe one keypress event == one letter. So you end up with yet another English-only (and I really do mean English specifically here, not Western European) and inaccessible rendering engine for a web page, that typically could have achieved 95-100% of what they wanted, with a bunch of the remainder being stuff that doesn’t work for people with accessibility issues.