Code examples

Guile is an implementation of the Scheme programming language, supporting the Revised5 and most of the Revised6 language reports, as well as many SRFIs. It also comes with a library of modules that offer additional features, like an HTTP server and client, XML parsing, and object-oriented programming.

;;; Hello world program
(define name "World")
(display (string-append "Hello " name "!"))

Hello world program

Define a variable called name, join the texts Hello, name, and ! together to form the greeting Hello world!, and display it on the screen.

;;; Show current date and time
(use-modules (srfi srfi-19))

(display (date->string (current-date)
                       "~A, ~B ~e ~Y ~H:~S"))

Importing modules

Import the srfi-19 module and use its functions to display the current date and time in the format WEEKDAY, MONTH MONTHDAY YEAR HOUR:SECOND.

;;; Hello HTTP server
(use-modules (web server))

(define (my-handler request request-body)
  (values '((content-type . (text/plain)))
          "Hello World!"))

(run-server my-handler)

Hello HTTP server

Run a Web server that will return a response with the text "Hello World!" to every request sent by HTTP clients. Open http://localhost:8080/ to see the result.

Guile is an extension language platform

Guile contains an efficient compiler and virtual machine. It can be used out of the box to write programs in Scheme, or can easily be integrated with C and C++ programs.

Guile is the GNU Ubiquitous Intelligent Language for Extensions, and the official extension language of the GNU project.

Extend applications

In addition to Scheme, Guile includes compiler front-ends for ECMAScript and Emacs Lisp (support is underway for Lua), which means your application may be extended in the language (or languages) most appropriate for your user base. And Guile's tools for parsing and compiling are exposed as part of its standard module set, so support for additional languages can be added without writing a single line of C.

Guile empowers users with "practical software freedom"

Using any of the supported scripting languages, users can customize and extend applications while they are running and see the changes take place live!

Users can easily trade and share features by uploading and downloading the scripts, instead of trading complex patches and recompiling their applications.

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Applications using Guile

GNU Guix & GuixSD

Package manager and GNU distribution


Accounting software


Suite for Electronic Design Automation


The GNU debugger


GNU Guile 2.2.1 released

April 19, 2017

We are delighted to announce GNU Guile 2.2.1, the first bug-fix release in the new 2.2 stable release series. This release adds a "sandbox" facility that can run…

GNU Guile 2.2.0 released

March 16, 2017

We are pleased to announce GNU Guile 2.2.0, the first of a new stable release series. More than 6 years in the making, Guile 2.2 includes a new optimizing compiler…

GNU Guile 2.1.8 released

March 10, 2017

We are delighted to announce GNU Guile release 2.1.8, the next pre-release in what will become the 2.2 stable series. This release fixes a number of portability…

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