By Prince McLean

Published: 12:00 AM EST

Apple has published new terms for its registered iPhone developer agreement that defines new limits for "Apple Confidential Information" protected by the program's Non Disclosure Agreement, allowing developers new freedom to collaborate with each other, conduct developer training sessions, and print guides and tutorials.

The new terms [PDF] replace the previous all-inclusive NDA that broadly covered any discussion of the software and tools included in the iPhone SDK, which itself was available for anyone to download after agreeing to the NDA.

Developers complained that the overly strict NDA was preventing them from being able to help each other and share their experiences with other developers, resulting in an unnecessary drag on iPhone development efforts.

In response, Apple made an announcement earlier in this month that stated "We have decided to drop the non-disclosure agreement (NDA) for released iPhone software.

"We put the NDA in place because the iPhone OS includes many Apple inventions and innovations that we would like to protect, so that others don’t steal our work. It has happened before. While we have filed for hundreds of patents on iPhone technology, the NDA added yet another level of protection. We put it in place as one more way to help protect the iPhone from being ripped off by others.

"However, the NDA has created too much of a burden on developers, authors and others interested in helping further the iPhone’s success, so we are dropping it for released software. Developers will receive a new agreement without an NDA covering released software within a week or so. Please note that unreleased software and features will remain under NDA until they are released.

"Thanks to everyone who provided us constructive feedback on this matter."

The new agreement continues to restrict Apple Confidential Information, including "any Apple pre-release software (including related documentation and materials) and any information disclosed by Apple to you in connection with Apple Events or Paid Content."

The agreement defines Paid Content as "certain proprietary content (including, without limitation, video presentations and audio recordings) that Apple may make available to you from time to time for a separate fee."

That suggests Apple will begin distributing paid training materials through iTunes to developers, and may relate to the Apple University program that the company hired away a dean from Yale to help set up early next year. Apple already distributes confidential information to WWDC attendees through iTunes that can only be accessed by users with accounts with the appropriate access, although this content does not involve separate fees.