Comment Re:Yes (Score 4, Informative) 782
By the way, at the time I looked into iphone development, there was a non disclosure agreement that prevented you from publishing your sources. Is it still active? How are you supposed to comply with the GPL under NDA? Does that preclude you from using any GPL code?
It has been quite some time since this NDA has been lifted, which is why there are plenty of books and tutorials readily available for anyone to buy/read (this wasn't the case when the SDK was first released). These publications generally contain a healthy dose of source code, so obviously it's fine to share. The only significant NDA that still exists regarding the iPhone SDK only covers beta releases of the SDK, which are only available to people who have signed up for the paid developer program.