The world’s most advanced mobile platform.

iOS is the world’s most advanced mobile platform, redefining what can be done with a mobile device. The iOS SDK combined with Xcode tools make it easy to create apps that perform feats never before attempted. iOS 4 delivers several new multitasking services that allow your apps to perform tasks in the background while preserving battery life and performance. With the App Store present on every iOS device, and localized around the world, there is simply no platform more compelling for mobile developers.

Powerful Foundation
The amazing user experience of iOS is possible because of the powerful foundation upon which it is built. Derived from the proven core of Mac OS X, iOS has been streamlined to be compact and efficient, taking maximum advantage of the iPad, iPhone and iPod touch hardware. Technologies shared between iOS and Mac OS X include the OS X kernel, BSD sockets for networking, and Objective-C, and C/C++ compilers for native performance.
Cocoa Touch
Cocoa Touch is the programming framework driving user interaction on iOS. Using technology derived from Cocoa and the gorgeous Mac desktop, Cocoa Touch and the iOS interface were completely re-designed for multi-touch. Buttons, table lists, page transitions, and gestures on the iPhone are unique for the pocketable form factor, and all this UI power is available to developers through the Cocoa Touch frameworks.
Built upon the Model-View-Controller paradigm, Cocoa Touch provides a solid foundation for creating state-of-the-art applications. When combined with the Interface Builder developer tool, it is both easy and fun to use drag-and-drop to design the next great iOS application.
Strong low-level foundations enable fantastic high-level frameworks such as Game Kit for multiplayer gaming, Core Data, which offers high performance, yet easy-to-use data management, Core Animation for stunning effects, and the most innovative browser engine on mobile devices in WebKit.
Working together, the Cocoa Touch frameworks and powerful foundation provide a truly unique canvas upon which to create a new work of application art. Learn more

Graphics
The iOS delivers a wide-range of graphics capabilities, ranging from comprehensive 2D drawing to accelerated 3D rendering and direct access to the system’s video playback and capture capabilities. Accessible through high-level frameworks, these capabilities make it easy to create gorgeous animations and transitions within your application’s UI. Learn more
Easy to Get Started
The complete Xcode developer tools and iOS SDK are distributed together, available as a free download simply by registering as an Apple Developer. Your first application will be running in the Simulator within minutes of installing the toolset, and when you’re ready to test and deploy on an iPad, iPhone or iPod touch, the iOS Developer Program will guide your way.