Page "Common Lisp" Paragraph 28

Most of the Lisp systems whose designs contributed to Common Lisp — such as ZetaLisp and Franz Lisp — used dynamically scoped variables in their interpreters and lexically scoped variables in their compilers.

Scheme introduced the sole use of lexically scoped variables to Lisp ; an inspiration from ALGOL 68 which was widely recognized as a good idea.

CL supports dynamically scoped variables as well, but they must be explicitly declared as " special ".

There are no differences in scoping between ANSI CL interpreters and compilers.