Jeff Tunnell was still an employee of Dynamix when I left the company. He was running his own game development subsidiary (I forget the name).
I spoke to Jeff a few years ago, and he mentioned that he negotiated a deal with Sierra for the engine from the last game he was working on, and was planning on selling games based on it. I think there was some deal under which his games could be marketed by Sierra (or, Dynamix).
I suggested he package up the engine, and market it to others, and make money selling the engine, rather than building products.
Jeff did this, and has a company going under the name: garagegames.com
As far as I know, he is doing very well.
-Ken W