Guile

Guile is the GNU Ubiquitous Intelligent Language for Extensions, the official extension language for the GNU operating system.

Guile as a programming language

1. Guile is an interpreter and compiler for the Scheme programming language.

1. Guile has fully support of R5RS, most of the R6RS, many SRFI.

GOOP

GOOPS is the object oriented extension to Guile.

Guile as an extension language platform

1. Guile is a virtual machine that executes a portable instruction set generated by its compiler.
2. Guile can integrate very easily with C and C++ application code.
3. In addition to Scheme, Guile includes compiler front-ends for ECMAScript and Emacs Lisp.

Emacs and Guile

Guile team has a long-term plan to replace the elisp engine in emacs with his own.