Swift
A fast, safe, modern language for everything from apps to servers.
Overview
Swift is the language Apple platforms are built around. It reads like a scripting language but compiles to fast native code, and its type system catches whole classes of bugs, like nil crashes and data races, before you run anything.
It's open source, runs on Linux, Windows and embedded devices too, and every Apple framework is designed with it in mind.
Optionals
Values that might be missing are marked in the type, so nil crashes become compile errors.
Structured concurrency
async/await, tasks and actors make concurrent code read top to bottom.
Protocols and generics
Write code once and reuse it across types without giving up speed.
Macros
Generate repetitive code at compile time. @Observable and #Preview are macros.
History
How it grew up.
Introduced
Announced at WWDC14 as a modern successor to Objective-C.
Open source
Swift is open-sourced, with Linux support from day one.
ABI stability
Swift 5 ships in the OS, so apps no longer bundle the runtime.
Concurrency
async/await and actors arrive in Swift 5.5.
Macros
Swift 5.9 adds macros that generate code at compile time.
Swift 6
Data-race safety is checked by the compiler.
Android
Swift 6.3 ships the first official Swift SDK for Android.