Ex-Apple engineer Terry Lambert responsible for a large portion of the OS X kernel took to Quora to answer a question about the genesis of the iPhone, and surrounding secrecy.
In the Quora post asking about the original iPhone, Lambert claims that he wrote 6% of the MacOS Kernel as measured by lines of code, or about 100,000 lines a year, much of which was repurposed for the iOS kernel.
Calling the original effort "Project Purple," Lambert said that he was brought in "late in the game" and mostly for debugging purposes. The engineer discussed not even seeing the product he was working on initially.
"I got taken into areas where there were black cloths everywhere," said Lambert. "I only got to see the machine doing the remote debugging, not the target — but it was obviously an ARM based system."
Lambert confirmed the suspicion that Apple uses multiple names for the same project, probably as an effort to suss out leakers.
"Another thing that Apple does is they give different code names to different groups," recalled Lambert. "In other words you may be working on the same project as someone else, and not actually know it. Or be allowed to discuss it."
Apple CEO Steve Jobs famously had tiers of access to the building that the iPhone was being developed in. In a form of compartmentalized security, engineers working on the least secret aspects of the program were limited to just that aspect, with workers involved on the core of the hardware, including the material design, had many tiers of security to pass thorough.
"You may have access to the regular lab, but not the 'secret lab,'" said Lambert. "You didn't really get to see the form factor, because when you are doing the initial work, it's all prototypes on plexiglass."
Lambert worked for IBM for several years in the '90s before joining Apple in 2003. The coder left Apple in Oct. 2010 to spend about two years at Google.