Xcode is Apple's integrated development environment (IDE): one application that combines a code editor, build tools, a debugger and testing tools. It runs only on the Mac and is used to develop, test and distribute apps for Apple platforms, mainly in the Swift programming language with interface frameworks such as SwiftUI, UIKit and AppKit.
Xcode Previews show a live view of the interface next to the code. Simulators and the Device Hub run the app on simulated and physical devices. Tests are written with Swift Testing or XCTest, and Instruments shows CPU, disk, memory and GPU use over time. Xcode Cloud is a continuous integration and delivery service, which builds and tests each code change automatically. Version 27 adds coding agents and models from Anthropic, Google and OpenAI inside the editor.
Xcode is a free download from the Mac App Store. A free Apple Account is enough to run apps on a device; publishing on the App Store requires membership in the Apple Developer Program.