[solarkraft]

> XUL has a single implementation

What's the issue with that? GTK, WPF Qt, Flutter ... all have a single major implementation.

> for the most part a single application suite actually using it

That is now, but it could've been a lot different.

I'm not that familiar with XUL (I'm just old enough to experience it being phased out) but it appears like a great idea to me: XML is not exactly bad for a UI, but XAML is Microsoft-specific (and not exactly great) and HTML is made for documents (leading to problems with worries about semantic tags, lack of layout features ...).

I also quite like how well Firefox integrates with all kinds of platforms. But who knows, maybe that's not in XUL, but specific to FF.