https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/AboutTheLanguageReference.html#//apple_ref/doc/uid/TP40014097-CH29-XID_453

关于Swift的苹果官方文档

https://itunes.apple.com/us/book/the-swift-programming-language/id881256329?

mt=11

IBook上的图书链接

个人使用网络的格式转换工具转的一篇pdf版

 http://dw4.convertfiles.com/files/0511329001401774160/the%20swift%20programming%20language.pdf 

https://developer.apple.com/library/prerelease/ios/documentation/DeveloperTools/Conceptual/WhatsNewXcode/Articles/xcode_6_0.html#//apple_ref/doc/uid/TP40014509-SW2

Xcode6 新特性

https://github.com/trending?l=swift

github上Swift的Trending页面