Introduction

This document describes key developer-level features that were introduced in different versions of macOS.

These are the main websites where you can obtain macOS development support:

• developer.apple.com: The best source of official up-to-date technical documentation on macOS development

• https://developer.apple.com/macos: The macOS Dev Center homepage on the Apple Developer website

• https://forums.developer.apple.com/welcome: A dedicated Apple Developer Forum.

This document is not intended as a complete list of features or changes for each new version of macOS. Instead, it focuses on those features or changes that affect the development of third-party software, providing overviews of each along with insight into how and when you might use them to create your own software. Wherever possible, this document also provides links to other Apple conceptual and reference documentation for that feature or change.

For the complete list of new APIs added in the latest version of macOS, see macOS 10.12 API Diffs.

Organization of This Document

This document includes the following articles:

• macOS 10.13 describes the changes that were introduced in macOS 10.13.

• macOS Sierra 10.12 describes the changes that were introduced in macOS 10.12.

• macOS Sierra 10.12.1 describes the changes that were introduced in macOS 10.12.1.

• macOS Sierra 10.12 describes the changes that were introduced in macOS 10.12.

• OS X El Capitan v10.11.2 describes the changes that were introduced in OS X v10.11.2.

• OS X El Capitan v10.11 describes the changes that were introduced in OS X v10.11.

• OS X Yosemite v10.10.3 describes the changes that were introduced in OS X v10.10.3.

• OS X Yosemite v10.10 describes the changes that were introduced in OS X v10.10.

• OS X Mavericks v10.9 describes the changes that were introduced in OS X v10.9.

• OS X Mountain Lion v10.8 describes the changes that were introduced in OS X v10.8.

• OS X Lion v10.7 describes the changes that were introduced in OS X v10.7.

• OS X Snow Leopard v10.6 describes the changes that were introduced in OS X v10.6.