The iPhone SDK will allow third-party software development supported by Apple, and is likely to be accompanied by a slew of applications already created by developers who've been working with Apple over the past several months. One of the major criticisms of iPhone has been its closed operating system which prevents developers from extending the handset's utility via user-installable software. While Symbian, Windows Mobile, and Palm-based devices can be augmented by thousands of user-installable apps, iPhone users have thus far had to wait for Apple-controlled software updates to add functionality to their devices beyond so-called Web apps developed to run inside of iPhone's Safari Web browser.
A robust hacker community has shown, however, that developing applications for iPhone is quite doable. Without any support from Apple, developers have accessed iPhone's OS X operating system and built software packages that do everything from enable instant messaging to emulate classic video game consoles on the handset. As such, the iPhone community has been anticipating the release of the SDK for quite some time now.
As Apple traditionally makes new product announcements on Tuesdays, we'll keep a close eye on Apple.com tomorrow to see if the iPhone SDK is, in fact, delivered before month's end as promised.
Read more about a possible iPhone SDK delay in BusinessWeek's Byte of the Apple blog.