Xcode 8： https://developer.apple.com/xcode/
Xcode 8 includes everything you need to create amazing apps for iPhone, iPad, Mac, Apple Watch, and Apple TV. This radically faster version of the IDE features new editor extensions that you can use to completely customize your coding experience. New runtime issues alert you to hidden bugs by pointing out memory leaks, and a new Memory Debugger dives deep into your object graph. Swift 3 includes more natural and consistent API naming, which you can experiment with in the new Swift Playgrounds app for iPad.
如上图，点击“在Mac App Store中查看”，进入 App Store 中安装 Xcode，如下图：
Mac brew 安装软件（推荐）