.FAS File Extension

Compiled script written in AutoLISP, a variation of the LISP programming language used specifically for the extension of AutoCAD software; often used for creating macros that automate common processes within AutoCAD; can be used for distributing utilities that add new features to the software.

FAS files are commonly compiled using Visual LISP, an IDE that is included with some AutoCAD purchases.

Compiled Lisp (.LSP) file saved in the "Fast Save Lisp Format" by Interleaf or QuickSilver; contains compiled code that can be executed by the program; may be generated by selecting either the DTK→Compile→Buffer or DTK→Lisp→Compile menu commands.

FAS files are also called FASL (Fast Load) files.

NOTE: Broadvision acquired Interleaf in January 2000 and later renamed the InterLeaf software to QuickSilver.