Open sourcing Swift and components

The official version of open source Swift was first launched in December 2015. Since being opened up to wider community support and development, open source Swift continues to grow in both popularity and maturity in terms of the contribution of open source community and the addition of new features. The contributors to open source Swift include Apple, IBM, PayPal, and other industry and academic institutions.

The effort of the open source developer community is coordinated through the Swift programming language evolution (https://github.com/apple/swift-evolution) process. The process governs the evolution of Swift by defining the process for accepting new proposals, stating the goals for upcoming Swift releases, reviewing and tracking the status of proposals, and specifying the decision-making procedure for accepting or rejecting a proposal. The evolution process ensures that Swift can evolve into a robust language while imposing constraints to maintain application binary interface (ABI) stability. With ABI stability, the binary compatibility between applications and libraries is ensured with different Swift versions.

Open source Swift includes more than the specification of the Swift programming language. On the official website of open source Swift, https://swift.org/, there is information on the fundamental components for the language, including the Swift compiler, standard library, package manager, core libraries, test framework, and REPL/debugger.

The source code repositories for the fundamental Swift components are hosted on GitHub at https://github.com/apple/swift. The following diagram shows the main components in open source Swift:

The license for the open source Swift projects is Apache 2.0 with a runtime library exception (https://github.com/apple/swift/blob/master/LICENSE.txt) .The runtime library exception clause in such a license allows you to compile the code into the binary product and distribute it.