Programming in an Interactive Environment: the "Lisp" Experience

Lisp systems have been used for highly interactive programming for more than a decade. During that time, special properties of the Lisp language (such as program/ data equivalence) have enabled a certain style of interactive programming to develop. characterized by powerful interactive support for the programmer, nonstandard program structures, and nonstandard program development methods. The paper summa-rizes the Lisp style of interactive programming for readers outside the Lisp community, describes those properties of Lisp systems that were essential for the development of this style. and discusses some current and not yet resolved issues