"This document is an introduction into using Guile, the GNU extension language and system. Guile is a dialect of the Scheme programming language, and I will assume you're at least confident about the very basics of Scheme or LISP in general. However, Guile also allows application developers to integrate it into their code to provide scripting capability to it and extend the main Guile language with primitives specific to the application being extended. Exactly this is what I want to give a brief introduction to..." — via guile-devel —