Bonjour, also known as zero-configuration networking, enables automatic discovery of computers, devices, and services on IP networks using industry standard IP protocols. It is a key component of Apple applications (e.g., iTunes and iPhoto), and devices (e.g., Apple TV and AirPort). Developers can easily leverage Bonjour from both OS X and iOS. View Downloads and Documentation
The most widely-sold UNIX operating system, OS X combines a fully-conformant UNIX foundation with the richness and usability of the Macintosh interface. View Developer Documentation
WebKit is the open source web browser engine at the heart of Apple's Safari web browser on Mac, Windows, and iOS. It also provides a system-level framework engine that powers Dashboard, Mail, and many other OS X apps. Webkit Open Source Project
iOS and OS X
Command Line Tools
Download command line developer tools, including Apple LLVM compiler, linker, and Make.
Open Source in OS X
Learn about the 200+ open source projects that ship with OS X.
Mac OS Forge
Open development of select OS X projects.
Additional Developer Documentation
A collection of useful documents about open source.