Apple on Thursday released the second beta version of the software development kit (SDK) for building applications for the iPhone and the iPod Touch that includes an interface builder, the Xcode integrated development environment, the iPhone simulator, frameworks and samples, compilers, and the Shark analysis tool.

Developers who want to share their applications to the iPhone will have to apply for membership and download the SDK at Apple’s website.

When the first beta version of the SDK was launched on March 6, more than 100,000 iPhone developers have downloaded it in the first four days. 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. (more…)