I worked on this product for a year back in the day. The cool thing about MS ESP was that we used the FSX Engine for the "1000 foot experience". Everything looked great from far above, but not close by. The solution to this was that MS Train Simulator 2 made tons of improvements for the "1 foot experience". The idea was to include a "world editor" with world-wide geospatial data, too. https://youtu.be/GXzE1Yb54xU?t=406 The physics models of the planes and the trains were great, but obviously to be a generic simulator you needed to include physics engines for other types of objects like Cars. So we grabbed the physics engine of Forza and included it there. These things combined were honestly beautiful - and add to that the backwards compatibility with all the 3rd party FSX plugins/adds ons. Bummer that this is exactly when the iPhone came out and the cloud-based strategies were taking over "classic" enterprise software. Re-org and bye bye FSX/TrainSim2/ESP. I had left before this happened, but was really a bummer not to see the full potential of ESP :-(