His Steveness has just performed an abrupt about-face, announcing today (and confirming recent rumors) that Apple will allow native third-party development on the iPhone starting in February.

In a letter posted on Apple's Web site, Jobs wrote: "We are excited about creating a vibrant third-party developer community around the iPhone and enabling hundreds of new applications for our users."

It's quite a reversal from just a few months ago, when Jobs & Co. insisted that opening up the iPhone to third-party applications would threaten the integrity of the device. As recently as last month, an Apple exec said that while Cupertino didn't "hate" outside applications on the iPhone, it didn't "like" or "support" them, either. And of course, Apple's recent software update wiped out any and all third-party apps installed on hacked iPhones.

In his letter, Jobs said a software development kit for the iPhone wouldn't arrive until Feburary because, in part, Apple needs to protect the device from "viruses, malware, privacy attacks, etc...since the iPhone is the most advanced phone ever, it will be a highly visible target." He also said that native iPhone apps may require a digital signature that can be "traced back to a known developer."

It's pretty sad that Apple took so long to decide that open development on the iPhone would be a good thing—but now that the belated announcement has arrived, I think it's great news. The Palm, Windows Mobile, and Symbian platforms are literally swimming in great third-party apps that have added untold value to their respective handsets, and I can't wait to see what the iPhone development community has in store.

Related:
Steve Jobs Announces 3rd Party SDK for iPhone for February 2008 [MacRumors]