Apple introduced Swift at WWDC in 2014 as a successor to Objective-C for its platforms.
Swift was designed at Apple by Chris Lattner and a team of contributors. Apple announced it at the Worldwide Developers Conference in June 2014. The language aimed to provide modern safety and convenience while remaining suitable for software on iOS, macOS, watchOS, and tvOS.
Swift includes type inference, optionals, closures, and automatic memory management through reference counting. Its compiler and runtime can interoperate with Objective-C, allowing developers to add Swift to existing Apple codebases gradually.
Apple open-sourced Swift in December 2015. Although Swift became Apple’s preferred general-purpose language for new platform development, Objective-C remains important in older applications and frameworks. Swift is also separate from SwiftUI: Swift is the programming language, while SwiftUI is Apple’s declarative framework for building user interfaces.