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

Package manager and GNU distribution


Accounting software


Suite for Electronic Design Automation


The GNU debugger


GNU Guile 3.0.7 released

May 10, 2021

We are humbled to announce the release of GNU Guile 3.0.7. This release fixes a number of bugs, a couple of which were introduced in the previous release. For full details,…

GNU Guile 3.0.6 released

April 28, 2021

We are pleased to announce the release of GNU Guile 3.0.6. This release improves source-location information for compiled code, removes the dependency on libltdl, fixes some…

GNU Guile 3.0.5 released

January 7, 2021

We are delighted to announce the release of GNU Guile 3.0.5. This release adds optimizations that can turn chains of repeated comparisons, such as those produced by the case…

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