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

The iPhone SDK provides developers with the same tools Apple uses to create its native applications for the 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 Phil Schiller, Apple’s senior vice president of worldwide product marketing.

Schiller confirmed over one million people have watched the launch video on

Developers chimed in with positive reaction to Apple's news.

“We’re very excited about Apple’s new SDK and reaching every iPhone user through the new App Store,” said Scott Rubin, vice president, sales and marketing, Namco Networks. “We can’t wait to show off great new versions of arcade classics like PAC-MAN and Galaga that use the revolutionary features of the iPhone and iPod touch.”

“Six Apart pioneered the mobile blogging experience with an iPhone-optimised blog service,” said Chris Alden, CEO, Six Apart. “We’re taking it to the next level with our native iPhone application for TypePad that’s already in development.”