Comment by imbnwa

Isn't this what XUL was? Admitedly I'm aware its arch was too complex to compete with Chromium's speed and security features, but way before Electron, I was using desktop apps built with XUL like Songbird for my music app, as well as a Twitter client whose name I can't recall now (of course, Thunderbird as well). Maybe they threw the baby out with the bath water a little bit by electing to concede to WebExtensions API since now Electron (read: Chromium) is filling exactly the niche that XUL provided.