I don't think there are many companies that use it as a primary language (maybe a few in clojure) - but I'm confident that learning a lisp dialect or other functional language makes you a more rounded programmer. Once you have a grasp of functional concepts you can easily port these to other languages and there is some demand in those languages (Scala, F#).

Also a lot of languages are starting to adopt features from the functional paradigm and it's always good to know where they came from. It's unfortunate that many engineers use techniques like memoization (via annotations for example) without understanding their underlying principles.

As for significant systems, Emacs is probably the most well known. Also the Clojure community is very active.

So the answer is no then.

Op is posting about learning cobol for job prospects, so an esoteric fad language without job prospects is probably not the language they are after.

I mean if looking directly at the market for job prospects yes, if becoming a good engineer and being able to excel in those roles it's a different thing - at 14 exploring various technologies is not only beneficial but also enjoyable.

Also Lisp is far from an "esoteric fad language", it's been around since the 1960s, has both ISO and ANSI standard dialects, and has some significant usage in industry. Like COBOL most of the companies that use Lisp are using it in specialized situations (I would argue this is similar for most functional languages). I feel like it's not talked about as much as COBOL because for COBOL specifically there is a market demand to maintain legacy systems that outstrips the supply. Because of this the role of maintaining these systems - at least historically - paid very well.

Maybe the original post should have been prefaced with ‘I know you’re specifically asking about job prospects, but here’s a language without job prospects that I think is cool’. I’m not saying that learning lisp would be a mistake, and not saying op could do with some guidance relating to which languages to learn, but I don’t think the original post is a good way of discussing either and imo is misleading in what it presents. I also don’t think a 14 year old learning to code should start with lisp.