https://developer.apple.com/news/?id=12032015a
Swift is Now Open Source
December 3, 2015
Join the open source community at Swift.org and help make the Swift programming language even better. You can now collaborate with other advanced developers to directly contribute features and enhancements, fix bugs, and help bring Swift to new platforms. Open source Swift includes support for building apps for iOS, OS X, watchOS, tvOS — and now, Linux. We’re excited to see where the community will take this language. To learn more, read the Swift blog.
swift 开源的好处: 增加新feature,fix bugs,移到其他平台,now Linux