This is a system for automatic grading of computer programs. It has been working for many years and is used in over 30 Universities throughout the world. This is the only system I could find that is in wide spread use. If readers know of any other systems that are used by people other than their developers I would be most interested to hear of them . There are some systems that have been developed but are not in widespread use.
Testing is a related area.
The Ceildih system shows it is possible so I don't think difficulty is the problem. This is more likely. University instructors rarely have the resources to purchase commercial software in quantity. Even if they do have the resources their inclination is to believe they can do it better themselves. This means that software systems like Ceildih have difficulty finding a market that will pay enough for the development.