This software was a cohort system. (Search for the cohort if you like.)
I had written a very intelligent, automated and dynamic system that would have added questions, groupings, features, and so on without programming. At the time I wrote this software, I thought it was a bit complicated and hard. But now I take the hard word. It's complicated. But it's not hard for me anymore :-)
One of the features of this software was a questionnaire. But not a simple questionnaire. A dynamic questionnaire that we could give any kind of question. Multiple choice questions, numeric, contextual, list, etc. We could even link other questions to other questions.
The security controls and the correctness of the answers were completely intelligent and automated.
Let me not to say many details about this project for now :-)