[sophiebits]

HTML parsing is well-specced these days.

[berkes]

The parsing is easy. And done in many, many libraries outside of the browsers. (And no, parsing with regex is still not possible, zalgo)

The problem is not parsing of HTML, its the DOM events, CSS application, javascript apis and above all the combination thereof which must be rendered all exactly the same, what makes it hard.

[boondaburrah]

parsing was never so much the problem as what was rendered afterwards being different.