The most frustrating thing is when the docs have that "this document is no longer maintained. Please see /documentation/whatever for the latest version" but when you go the link it ends up just linked back to the place you came from. I guess that means the unmaintained stuff is still current? I don't know though because it's still all Objective-C, so I have no idea what the current best practice is supposed to look like. For a trillion dollar company it's kind of annoying that they can't hire somebody to do the docs. For MacOS dev there are basically no third party resources either. The last book is from Swift 3. It's better than nothing, but not much.