Swift has got a major upgrade to Swift 2 and was announced in WWDC 2015. Originally a proprietary language, version 2.2 was made open source and released under the Apache License 2.0 on December 3, 2015 for Apple platforms and Linux.
I’m quoting the following message from swift.org
Swift is now open source!
We are excited by this new chapter in the story of Swift. After Apple unveiled the Swift programming language, it quickly became one of the fastest growing languages in history. Swift makes it easy to write software that is incredibly fast and safe by design. Now that Swift is open source, you can help make the best general purpose programming language available everywhere.
For students, learning Swift has been a great introduction to modern programming concepts and best practices. And because it is now open, their Swift skills will be able to be applied to an even broader range of platforms, from mobile devices to the desktop to the cloud.
Welcome to the Swift community. Together we are working to build a better programming language for everyone.
– The Swift Team
Swift 2.2 can now be installed on Ubuntu 15.10 or 14.04. Find out more here.