Lisp (historically LISP, standing for List Processing) is a family of Programming Languages with a long history and a distinctive, fully parenthesized prefix notation. Originally specified in 1958, Lisp is the second-oldest high-level programming language still in common use. Only Fortran is older, by one year.Lisp has changed since its early days, and many dialects have existed over its history. Today, the best-known general-purpose Lisp dialects are Racket, Common Lisp, Scheme, and Clojure.