Lisp was the main language of Symbolic AI. That market largely crashed in the 80s/90s. Planners&scheduling in the military&logistics (airlines, airports, train

Lisp was the main language of Symbolic AI. That market largely crashed in the 80s/90s. Planners&scheduling in the military&logistics (airlines, airports, train operators, satellites, ...), expert systems for maintenance, computational engineering systems (for example for airplanes from Airbus and Boeing), theorem provers (used in chip design), symbolic mathematics, natural language systems (text translation for the EU), ...