This document provides information on how to become an iPhone developer. It discusses what an iPhone is, how the iPhone has evolved over time, and the development approaches that can be used to create iPhone apps, including web applications and using Apple's SDK and tools like Xcode and Interface Builder. It also outlines the requirements needed to develop iPhone apps, such as an object-oriented programming background, an Intel-based Mac computer, an Apple Developer program membership, and either an iPhone or iPod Touch device.