Cocoa is a powerful set of frameworks on which OS X is built. Gain an overview of the advances in AppKit, Foundation, and related frameworks. Find out what technologies you need to focus on and what techniques you should adopt to develop state of the art apps for OS X. Start here for a high level view of what’s changed, and get pointers to relevant sessions for more depth.
WWDC 2015 > App Frameworks > What’s New in Cocoa