Swift is a new programming language for iOS,OS X,watchOS,and tvOS apps that builds on the best of C and Objective-C,without the constraints of C compatibility. Swift adopts safe programming patterns and adds modern features to make programming easier,more flexible,and more fun. Swift’s clean slate,backed by the mature and much-loved Cocoa and Cocoa Touch frameworks,is an opportunity to reimagine how software development works.

Swift是一个用来开发iOs和OS X app的新编程语言，其构建在C和Objective-C的最佳实践基础上，却没有C兼容性的约束。Swift采用了安全编程模式，增添了一些现代的特性，使得编程更容易、更灵活、更有趣。依靠成熟和深受欢迎的Cocoa和Cocoa Touch框架，Swift的清白历史带来重新构想软件开发方式的机会。

Swift has been years in the making. Apple laid the foundation for Swift by advancing our existing compiler,debugger,and framework infrastructure. We simplified memory management with Automatic Reference Counting (ARC). Our framework stack,built on the solid base of Foundation and Cocoa,has been modernized and standardized throughout. Objective-C itself has evolved to support blocks,collection literals,and modules,enabling framework adoption of modern language technologies without disruption. Thanks to this groundwork,we can now introduce a new language for the future of Apple software development.

Swift在市场上已经多年了。Apple通过推进我们现有的编译器、调试器和框架架构来为Swift打下基础。我们通过自动引用计数（ARC）简化了内存管理。我们的框架栈，构建在Foundation和Cocoa的坚实基础上，已经彻底现代化和标准化。Objective-C自身已经进化到支持块、集合字面值和模块，使得框架能够采用现代语言技术而不带来干扰。感谢这个基础，我们现在可以为Apple软件开发的未来引进一个新的语言。

Swift feels familiar to Objective-C developers. It adopts the readability of Objective-C’s named parameters and the power of Objective-C’s dynamic object model. It provides seamless access to existing Cocoa frameworks and mix-and-match interoperability with Objective-C code. Building from this common ground,Swift introduces many new features and unifies the procedural and object-oriented portions of the language.

Swift对Objective-C开发者来说会感觉熟悉。它采用了Objective-C的命名参数的可读性，Objective-C的动态对象模型的强大能力。它提供了对现存Cocoa框架的无缝访问，以及和Objective-C代码的混搭互操作性。构建在这个共同基础上，Swift引入了很多新特性，并统一了这个语言的过程部分和面向对象部分。

Swift is friendly to new programmers. It is the first industrial-quality systems programming language that is as expressive and enjoyable as a scripting language. It supports playgrounds,an innovative feature that allows programmers to experiment with Swift code and see the results immediately,without the overhead of building and running an app.

Swift对新开发者来说是友好的。它是第一个工业质量的系统编程语言，却象一个脚本语言一样富有表现力和愉快。它支持playgrounds，这是一个创新的特性，允许开发者尝试Swift代码并立即看到结果，不需要构建和运行app

Swift combines the best in modern language thinking with wisdom from the wider Apple engineering culture. The compiler is optimized for performance,and the language is optimized for development,without compromising on either. It’s designed to scale from “hello,world” to an entire operating system. All this makes Swift a sound future investment for developers and for Apple.

Swift结合了现代语言的优点，从广泛的Apple工程文化进行了创新思考。编译器为性能优化，语言为开发优化，不向彼此妥协。它被设计来从“hello,world”到一个全部的操作系统都可以胜任。这些使得Swift对于开发者和Apple都是一个良好的未来投资

Swift is a fantastic way to write iOS,and tvOS apps,and will continue to evolve with new features and capabilities. Our goals for Swift are ambitIoUs. We can’t wait to see what you create with it.