Good Afternoon All;
My apologies for the delay on posting this to Julie; apparently my spam filter was not fond of your email.
Attached is the famous 'onion' diagram illustrating the layered growth of VistA over the course of its history. This, combined with the VA's prioritization, has been shared with us to allow us to assist the community in prioritization of targets in the code convergence effort; in this we may target the core and iteratively expand our convergence efforts.
It is available in both power-point and pdf format.