David wrote "The Colony", the first real time 3D adventure shooter game in 1987. This game led to Jim Cameron asking him to build the first realtime 3D set for the movie "The Abyss" which led to the creation of Virtus Walkthrough, the first real time 3D design tool. Tom Clancy got hooked on The Colony and called David up about working together, so they co-founded Red Storm Entertainment and the created "Rainbow Six". David then collaborated with Alan Kay (Turing award winner, defined object oriented programming and is the father of the personal computer) . They invited David P Reed (created UDP and co-created TCP/IP) to join them to create the original Croquet multiplayer protocol in Smalltalk. David then joined Lockheed Martin as a Senior Fellow running their AR and VR projects. He founded Croquet Corp. with Brian Upton, game designer of "Rainbow Six" and "Ghost Recon", to reinvent multiplayer games. The Croquet OS won the Polys WebXR Platform of the Year. David also invented portals.