Apple

The Swift Programming Language

FoundationDB - the open source, distributed, transactional key-value store

The Foundation Project, providing core utilities, internationalization, and OS independence

The Package Manager for the Swift Programming Language

Turi Create simplifies the development of custom machine learning models.

The XCTest Project, A Swift core library for providing unit test support

Event-driven network application framework for high performance protocol servers & clients, non-blocking.

The libdispatch Project, (a.k.a. Grand Central Dispatch), for concurrency on multicore hardware

This maintains proposals for changes and user-visible enhancements to the Swift Programming Language.

This is the version of LLDB that supports the Swift programming language & REPL.

The Calendar and Contacts Server.

A Logging API for Swift

A Metrics API for Swift

Language Server Protocol implementation for Swift and C-based languages

Index database library for use with sourcekit-lsp

Stress testing utilities for Swift's tooling

Logging and communication to allow Swift toolchains to communicate with Xcode.

Automated tests for validating the generated Swift snapshots behave correctly

A low-level build system, used by Xcode and the Swift Package Manager

SwiftPM package for SwiftSyntax library.

HTTP/2 support for SwiftNIO

Official CUPS Sources

Extensions for SwiftNIO to support Apple platforms as first-class citizens.

Useful code around SwiftNIO.