Note: The second edition of this book, titled macOS App Development: The SwiftUI Way, has been released with substantial changes and upgrades for Xcode 15. Please consider checking out this updated version instead.Introduced in 2019, SwiftUI is a user interface toolkit that let you create applications with the power of the programming language Swift for all Apple platforms, including iOS, tvOS, watchOS, and macOS.Before the launch of SwiftUI, developers had to use platform-specific UI frameworks to develop user interfaces, for example, AppKit for macOS apps, TVUIKit for tvOS, and WatchKit for watchOS apps. SwiftUI becomes the one unified UI framework for building user interfaces for all Apple devices.This book will primarily focus on building macOS apps with SwiftUI, including both coding and releasing apps.