The Swift Programming Language
This maintains proposals for changes and user-visible enhancements to the Swift Programming Language.
The Package Manager for the Swift Programming Language
The LLVM Project is a collection of modular and reusable compiler and toolchain technologies. Note: the repository does not accept github pull requests at this moment. Please submit your patches at http://reviews.llvm.org.
The Foundation Project, providing core utilities, internationalization, and OS independence
The libdispatch Project, (a.k.a. Grand Central Dispatch), for concurrency on multicore hardware
Testing HTTP requests has never been easier. Nocilla: Stunning HTTP stubbing for iOS and Mac OS X.
The XCTest Project, A Swift core library for providing unit test support
A low-level build system, used by Xcode and the Swift Package Manager