Apple has announced via its Apple Developer Connection website that it has dropped the NDA that has left iPhone developers frustrated since the release of iPhone OS 2.0 this past July. In a note addressed "To Our Developers," Apple finally admitted that the NDA had "created too much of a burden on developers, authors and others interested in helping further the iPhone’s success."

Apple had, like most companies, attached a nondisclosure agreement to developers that wanted early access to the SDK before iPhone OS 2.0 was released. Nearly everyone involved in iPhone development expected the NDA to be lifted once 2.0 was officially released. Apple unexpectedly kept the NDA in place, however, and offered no explanation to developers—nor did it offer a timetable on when it might be lifted. This caused serious problems for those who had books ready to be published to help new developers, as well as programmers wanting to post to blogs or forums discussing iPhone programming tips and techniques. The prohibition on blog and forum posts also made it difficult for developers to get help when they run into trouble.

There was a lot of speculation about Apple's reasoning for keeping the NDA in place, including slow-moving bureaucracy and sheer ignorance, though protecting IP seemed most reasonable. Apple said in Wednesday's note that protecting IP was its reason for keeping the NDA in place. "We put it in place as one more way to help protect the iPhone from being ripped off by others," reads the note.

From what we're seeing on Twitter, the collective iPhone developer community couldn't be more delighted. "Ok. I'm back in on iPhone dev," said Second Gear's Justin Williams. Jonathan Wight, developer of the TouchCode frameworks, said, "I now have a whole bunch of code to put online." Addison-Wesley Senior Acquisitions Editor Chuck Toporek, on his way to inform production to start printing The iPhone Developer's Cookbook, stopped to say, "Thank you, thank you, thank you!" Even one of the NDA's most fervent detractors, Twitterrific developer Craig Hockenberry, joked, "The downside, of course, is that I need to find something else to be bitter about. Anyone want to get on my lawn?"

"I think this will really open the floodgates for iPhone development. An open exchange between developers is crucial on any platform, and with the shackles off, iPhone will flourish," says Ben Gottlieb, developer of Crosswords for iPhone. "Kudos for Apple to listening to the developer community and adjusting their position. Any increase in transparency is a welcome change, and hopefully this is a sign of more good things to come," he tells Ars.

Though Apple has said nothing about the recent issues regarding App Store rejections, this is certainly a major step toward regaining developers' trust. Of course, Apple will still keep unreleased versions of the iPhone OS and beta SDKs under NDA. But as with Mac OS X, iPhone developers are free to publicly discuss any APIs or other features in released versions. This will certainly go a long way towards maintaining a large and vibrant developer community.

The NDA's demise also means that we can finally run our in-depth probe into the iPhone SDK. Look for it this evening.