Virtual Reality Studio from DOMARK (1991) is a 3D development environment for DOS. You can create 3D graphics and even code for games. It is a lot of fun to use, powerful for the time and could still be used as a great teaching tool even today! I say that as a Computer Science teacher of 20 years. Watch the entire video to see Virtual Reality Studio in action.
Virtual Reality Studio - Software of the year in 1991 - ACE Magazine.