[davidbalbert]

In response to:

> Fun aside: I’ve always assumed this is why Core Foundation exists—to provide a common interface between Carbon and Cocoa. I don’t actually have a citation for this, though.

This (very enjoyable) blog post from 2006 confirms it: https://ridiculousfish.com/blog/posts/bridge.html. I believe ridiculous_fish was working at Apple at the time.

[saagarjha]

Of course, while toll-free bridging is still around, its implementation details are somewhat different these days.