Lisp is a family of programming languages that includes Common-Lisp, Emacs-Lisp , Interlisp?, ZetaLisp?, and Maclisp , among others. Scheme, according to most Schemers, is also firmly within this family. Some Common Lispers enjoy denying Scheme the status of a Lisp; oft cited is R5RS's formal syntax, which defines Scheme's syntax in terms of a token stream instead of Lisp objects, i.e. lists, symbols, et cetera. However, Lisp is just a name, and whether Scheme is a Lisp is a purely conventional question of what you definition of Lisp happens to be: the whole issue is purely nominal.

According to McCarthy Lisp is categorized by the following ideas