Programming languages are not natural features of the computer landscape, though students are often expected to study them as if they were. They have histories; they are invented, struggle for popularity, and eventually decline. Very few languages have been in steady use since the early 1960s, and LISP is one of them. (FORTRAN is another.)

LISP stands for LISt Processing language. Despite its specialized-sounding name, LISP is a general-purpose programming language like C, FORTRAN, and scores of others. Programs can be written in LISP to do whatever other computer languages do. As a result of this broad overlap, there is often debate among programmers about which language is best for this or that programming job. LISP was, however, invented in the late 1950s as a tool for research in artificial intelligence (AI). Its still one of the most commonly used languages in AI research, and is usually characterized...