A language is stable if there is wide spread agreement among its users about what features are part of the language. Stability is achieved through an official or semi-official description of the language. Unfortunately, major differences between LISP dialects developed soon after it was introduced. Eventually programs written in one dialect wouldn't run using an interpreter for another. Some of the most popular dialects are shown in the diagram below.
Arrows indicate which dialects influenced others.
In 1980 work began on a standard dialect called Common LISP . Common LISP is now widely accepted by industry, and an ANSI standard is about to appear. Scheme I like the Scheme programming language because it is small. It packs a large number of ideas into a small number of features. Guy Steele Jr. The dialect of LISP used in this text is called Scheme .