I agree, but also it’s the fact that there’s a steady supply of devs who already know decent HTML, while not many who know XUL. It would be easy to apply your HTML knowledge to XUL, but since we already support interleaving HTML and XUL, why not let people just use what they’re used to?

That said, I didn’t really look into it all that much! I just happen to know about it because I was doing some userChrome.css stuff back in the day.

Just came across this Firefox.html announcement in another thread and it might have some more context: https://web.archive.org/web/20230402033035/https://mail.mozi...