The iPhone SDK provides developers with the same set of Application Programming Interfaces (APIs) and tools that Apple uses to create its native applications for iPhone and iPod touch.

“Developer reaction to the iPhone SDK has been incredible with more than 100,000 downloads in the first four days,” said Philip Schiller, Apple’s senior vice president of Worldwide Product Marketing. “Also, over one million people have watched the launch video on Apple.com, further demonstrating the incredible interest developers have in creating applications for the iPhone.”

Apple also previewed the new App Store, as way for developers to wirelessly deliver their applications to every iPhone and iPod touch user. Developers set the price for their applications—including free—and retain 70 percent of all sales revenues.

Leading developers such as AOL, Electronic Arts, Epocrates, salesforce.com and Sega have already demonstrated amazing applications using the SDK, and developer response continues to be phenomenal with more developers embracing the platform.