Introduction

This document describes developer-level features that were introduced in different versions of iOS. For each shipping release, this document provides links to “delta” reference documents, which list the new and changed programming interfaces that were introduced in that release.

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

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

• developer.apple.com/ios: The iOS Dev Center homepage on the Apple Developer website

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

Organization of This Document

This document includes the following articles:

• iOS 11.0 describes the new and updated features in iOS 11.0.

• iOS 10.3 describes the new and updated features in iOS 10.3.

• iOS 10.2 describes the new and updated features in iOS 10.2.

• iOS 10.1 describes the new and updated features in iOS 10.1.

• iOS 10.0 describes the new and updated features in iOS 10.

• iOS 9.3 describes the new and updated features in iOS 9.3.

• iOS 9.2 describes the new and updated features in iOS 9.2.

• iOS 9.1 describes the new and updated features in iOS 9.1.

• iOS 9.0 describes the new and updated features in iOS 9.

• iOS 8.4 describes the new and updated features in iOS 8.4.

• iOS 8.3 describes the new and updated features in iOS 8.3.

• iOS 8.2 describes the new and updated features in iOS 8.2.

• iOS 8.1 describes the new and updated features in iOS 8.1.

• iOS 8.0 describes the new and updated features in iOS 8.

• iOS 7.1 describes the new and updated features in iOS 7.1.

• iOS 7.0 describes the new and updated features in iOS 7.

• iOS 6.1 describes the new and updated features in iOS 6.1.

• iOS 6.0 describes the new and updated features in iOS 6.

• iOS 5.1 describes the new and updated features in iOS 5.1.

• iOS 5.0 describes the new and updated features in iOS 5.