When Apple first revealed Swift 2.0 at WWDC in June, the company said that the programming language would be going open source by the end of the year. Well, the wait is over as Swift is now officially open source.
This programming language will be released under the Apache 2.0 license, meaning that all of the source code, including the code for a new package manager, will be available to edit and compile and programs can be created without attribution. Included in this release are the compiler, the LLDB debugger, the REPL command-line environment, the standard and core libraries, and code from supporting projects.
In tandem with Swift going open source, Apple has launched Swift.org, providing tutorials and documentations surrounding the programming language. Besides that, the website also hosts a blog where Apple will update developers about the next iteration of Swift, Swift 3.0. According to Apple, one of the major goals for Swift 3.0 is source compatibility. This means that code writen to target Swift 3.0 will continue to compile properly even as the language continues to develop. As older Swift versions do not come with this feature, Apple has warned developers that things are going to break between the current version of Swift and Swift 3.0.
Source : Ars Technica