LISP, ALGOL, BASIC, and C

John McCarthy, a mathematician at MIT, designed LISP (LISt Processing) in 1958, introducing recursive functions, symbolic expressions, and the now-ubiquitous idea of treating code and data uniformly as lists. LISP pioneered automatic garbage collection, the automatic reclamation of unused memory, and became the foundational language of early artificial intelligence research, used for decades at MIT, Stanford, and other research centers. Its minimalist, parenthesis-heavy syntax and its emphasis on functions as first-class values established the functional programming paradigm that would later influence languages ranging from Scheme and ML to the functional features found in modern Python and JavaScript.