AppKit

AppKit contains the objects you need to build the user interface for a macOS app. In addition to drawing windows, buttons, panels, and text fields, it handles all the event management and interaction between your app, people, and macOS. Aside from drawing and managing interactions, AppKit handles printing, animating, as well as creating documents with large amounts of data efficiently. The framework also contains built-in support for localization and accessibility to ensure that your app reaches as many people as possible.