"Apple is kicking that final item off today by releasing a version of Swift that works on Linux. This is likely meant for Apple's enterprise partners, like IBM, who will now be able to create the consumer-facing portion of apps in Swift and have them talk to Linux servers that speak Swift as well."Craig Federighi talks open source Swift and what’s coming in version 3.0 | Ars Technica
"Swift is being released under an Apache 2.0 license, which is incidentally the same license Microsoft used when it open-sourced a big chunk of its .NET framework last year. The project will be hosted on GitHub and will include the compiler, the LLDB debugger, the REPL command-line environment, the standard and core libraries, and code from supporting projects."
Swift.org - Download Swift
Apple Open Sources Swift @ InfoQ
IBM's Swift Response @ InfoQ