Swift 5.0 Release Process

The primary goal of Swift 5.0 is for the language to achieve ABI stability. This will enable a stable Swift runtime to be deployed by OS vendors that can be linked against by executables and libraries.

Related to ABI stability, module stability will be a primary focal point as well. This will land in either the Swift 5.0 release or in a subsequent 5.x release depending on its readiness.

→ swift.org/blog/5.0-release-process/

Swift 5.0 aims to achieve ABI stability to enable a stable runtime for operating systems, with module stability as a key focus that may land in this release or a later 5.x update. It lacks binary compatibility with prior versions but ensures future releases will be compatible with it, while maintaining source compatibility with Swift 4.2 and dropping support for Swift 3 mode.

The swift-5.0-branch, already cut from master, receives periodic merges until 16 November 2018, after which only critical fixes enter via pull requests, with some repositories like swift-package-manager having extended deadlines.

Language and API changes require Swift Evolution approval, and other modifications are evaluated based on risk, with criteria growing stricter as the release approaches.