The first widely used programming language developed for AI applications
was the functional language LISP (McCarthy et al., 1965), which appeared
in 1959. Most AI applications developed prior to 1990 were written in LISP
or one of its close relatives. During the early 1970s, however, an alternative
approach to some of these applications appeared—logic programming using
the Prolog (Clocksin and Mellish, 2003) language. More recently, some
AI applications have been written in systems languages such as C. Scheme
(Dybvig, 2003), a dialect of LISP, and Prolog are introduced in Chapters 15
and 16, respectively.