Apple must be given some credit for the ARM chips it has in its iPad and smartphones. It does spend time and money developing them. Does it have co-developers on ARM chips? I’m not sure at this point
Apple has zero participation in the Intel chips it uses except for its cute habit of ordering odd frequencies that you cannot get elsewhere. For example its iMac would have an Intel Core2 chip @2.13MHZ. Everyone else would have the same chip but at 2.00 or 2.25GHZ
Apple is obviously working with Imagination too. Other than that, I'd bet the expertise of the former PA Semi and Intrinsity can probably handle anything. It's going to suck for Samsung to lose that expertise for future generations, since I doubt Apple will be hiring out.
Apple has zero participation in the Intel chips it uses except for its cute habit of ordering odd frequencies that you cannot get elsewhere.
Actually, there is an internal group at Intel specifically for Apple, and it includes Apple engineers. Their level of participation is unknown, but it must be some or the group wouldn't exist. At a minimum they must be working on customizations, such as the exclusive low-profile chip in the first MacBook Air. They probably also did extensive work in integrating Thunderbolt, and the small-package Thunderbolt controller for the Air.