I think originally Apple was using SproutCore, which had similar aspirations to produce "desktop quality" web apps, and was one of the early frameworks to imple

I think originally Apple was using SproutCore, which had similar aspirations to produce "desktop quality" web apps, and was one of the early frameworks to implement things like two-way data binding. This was back when iCloud was called MobileMe. SproutCore 2.0 became Ember.js 1.0, but I don't know if Apple are still using it.