Were you developing Expert Systems? Have any stories to share?

Question

I'm kinda fascinated by the subject of expert systems. Never have took any deep dive into them but they always existed somewhere in vicinity of my attention, I happened to read mentions of them. They kinda have fame of it's own. Like stuff in COBOL. Like "you better be prepared to work with their code base or scream loudly and run for your life in case of slightest mention of your team going to work with them". Any people around here worked with any of these systems? Are they really that scary?

Rochus · Accepted Answer

Yes, I had some projects in the late eighties/early nineties, with expert system shells like M4 by TechKnowledge, CLIPS by NASA and some homegrown shells based on Lisp or Objective-C. Not that scary at all, but the main challenge was the rules (where to get them from, what to do with incomplete or conflicting rules, etc.). CLIPS is still available (see https://www.clipsrules.net/) and very well documented.