There is only one file type that uses the .LISP extension:
Lisp Source Code File
Source code file written in Lisp, a programming language that has several different dialects including Common Lisp and Scheme; contains plain text program code that is run with a Lisp interpreter; may be an entire program or a part of a larger Lisp application.
LISP files can be edited with any text editor. However, they are more easily viewed and edited using an editor that supports Lisp syntax highlighting.
NOTE: Lisp has been widely used in the areas of artificial intelligence (AI), natural language processing (NLP), and symbolic processing.
Updated: September 14, 2010