My Dad used to use Intergraph at Abbott Laboratories in North Chicago. I remember him telling me when I was a kid, that he was being forced to go back to school because all these new youngsters fresh out of school who were leaps and bounds ahead of him in CAD (which was failrly new at the time - late 70's). So, he grudgingly spent all his free time going to the local college and learn Intergraph just to keep his job. He was a master on the board, and was just as skilled at airbrushed renditions. He finally retired as Senior Draftsman sometime in the 80's.