By AppleInsider Staff

Published: 08:00 AM EST

Apple said Wednesday that more than 100,000 iPhone developers have downloaded the beta iPhone Software Development Kit (SDK) in the first four days since its launch on March 6.

The iPhone SDK provides developers with the same rich 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.”

Last Thursday, Apple also previewed the new App Store, a 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 applications using the SDK, and developer response continues to be strong with more developers embracing the platform, according to Apple.

"Apple’s become an important mobile game platform with the iPhone SDK," said Jason Kapalka, co-founder and Chief Creative Officer, PopCap. "The new SDK gives us the tools to innovate and reinvent games like Bejeweled, Zuma and Peggle. With the new App Store we can reach every iPhone and iPod touch user on the planet."

The free beta iPhone SDK is available immediately worldwide and can be downloaded at Apple's developer website. The iPhone Developer Program will initially be available in the US and will expand to other countries in the coming months, Apple said.

A QuickTime video of the iPhone roadmap event remains available here, in both standard and high-definition formats.