The platform teams at Apple don't really work that way. My (limited) understanding is that they share a fair amount of core code, but each went their own way fo

The platform teams at Apple don't really work that way. My (limited) understanding is that they share a fair amount of core code, but each went their own way for a while and have recently started getting nudged back together from a UI perspective -- unfortunately, the iOS style guide seems to have won, and many decades of desktop UX is being thrown out with the bath water.