Flow browser

[zcorpan]

https://www.quirksmode.org/blog/archives/2020/01/new_browser_on.html

And something that was much easier to implement than you thought?

The HTML parser. I first wrote an HTML parser back in 2002, and back then there was no detailed specification of how to handle badly-nested elements. We spent so much time writing test cases to figure out what desktop browsers did in each situation, and trying to behave the same. Ten years later, the detail in the WHAT-WG specification was amazing, and it was perfectly possible to write an HTML parser that is completely compatible with all other browsers.