What is Swift? An innovative new programming language for Cocoa and Cocoa Touch. Writing code is interactive and fun, the syntax is concise yet expressive, and apps run lightning-fast. Swift is ready for your next iOS and OS X project — or for addition into your current app — because Swift code works side-by-side with Objective-C.
Swift is an open source tool with 48.2K GitHub stars and 7.71K GitHub forks. Here's a link to Swift's open source repository on GitHub.