Guile is an implementation of the Scheme programming language. Scheme (http://schemers.org/) is an elegant and conceptually simple dialect of Lisp, originated by Guy Steele and Gerald Sussman, and since evolved by the series of reports known as RnRS (the Revised^n Reports on Scheme).
Shell
(+ 1 2 3) ; add some numbers
$1 = 6
(define (factorial n) ; define a function
(if (zero? n) 1 (* n (factorial (- n 1)))))
(factorial 20)
(getpwnam \"root\") ; look in /etc/passwd
Script
#!~.guix-profile/bin/guile -s
!#
(display \"Hello, world!\")
(newline)