SwiftUI

SwiftUI is Apple’s declarative framework for building native user interfaces across all Apple platforms with a single, unified codebase.

This is Apple’s modern UI toolkit, leveraging the power of Swift to deliver a declarative syntax: you state what your UI should do, not how. It’s a unified system, meaning you write one set of code to deploy on iOS, iPadOS, macOS, watchOS, and tvOS (plus visionOS). Development is streamlined via deep integration with Xcode, offering features like real-time previews and automatic synchronization between the UI and app state. For existing projects, SwiftUI offers seamless interoperability with older frameworks like UIKit and AppKit, enabling incremental adoption without a full rewrite.

https://developer.apple.com/swiftui/