updated 04:24 pm EDT, Thu May 22, 2014
Also credited with number of other OS X, iOS technologies
John Harper -- the creator of the Core Animation framework used in iOS and OS X -- has left Apple for a position at Facebook, according to posts on Twitter. Core Animation first appeared in the iPhone OS in 2007, and migrated to OS X months later. Harper has spent over 12 years at Apple in total, and is credited with helping on a number of other iOS/OS X components as well, including Core Image, the port of X11, and OS X's windowing system.