Latest stable version: 3.33.0
Release date: December 3, 2019

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Logtalk runs on any operating-system with a standards compliant modern Prolog compiler. The interface between Logtalk and a specific backend Prolog compiler is accomplished using a small adapter file. The Logtalk distribution includes adapter files for all supported Prolog compilers:

Legacy Logtalk versions (2.x) provide support for several other Prolog compilers, which are no longer supported due to lack of compliance with official and de facto standards.

Be sure to install the Prolog systems that you want to use as backend compilers before installing Logtalk. In general, it is recommended that you install the most recent versions of the Prolog systems.


Logtalk is an open source programming language, distributed under the Apache License 2.0. The copyright notice and license applies to all files in this release (including sources, documentation, and examples) unless otherwise explicitly stated (see the NOTICE.txt file for details on bundled third-party resources).

Git repo

The Logtalk git repo is currently hosted at GitHub. Follow these steps for running Logtalk development versions. See the release notes for the latest changes.

You may keep up to date on development changes by subscribing to the Logtalk commits RSS feed.


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Includes the HTML versions of the Handbook and the APIs documentation. The bundled file contains manual installation instructions.


Be sure to read the,, and files on the Logtalk user directory for important information, including instructions on how to customize and run Logtalk. For Windows users, this information is also available from the Logtalk program group in the Start Menu.

The following installers are available for the latest version:


Based on the MacPorts portfile. Installs Logtalk on /opt/local/share/ with integration scripts for supported Prolog compilers on /opt/local/bin. Creates an /Applications/Logtalk folder with links to the installed files.
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A MacPorts portfile is also available. Users may simply type the command sudo port install logtalk (or sudo port upgrade logtalk) in order to install (or upgrade) Logtalk. Homebrew users may simply type the command brew install logtalk (or brew upgrade logtalk) in order to install (or upgrade) Logtalk. But do check first that the MacPorts portfile and the Homebrew formula are up-to-date.


Installs Logtalk on /usr/local/share with integration scripts for supported Prolog compilers on /usr/local/bin.

defb45936c962bb1cd4c62ff6ef4ffb27ef11c564f175f54735f53218bd8bc23 (SHA-256)

Package installation from the command-line is recommended:

$ sudo rpm -i logtalk-3.33.0-1.noarch.rpm

Debian (e.g. Ubuntu)

Requires dpkg 1.15.0 or a later version. Installs Logtalk on /usr/share with integration scripts for supported Prolog compilers on /usr/bin.

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Package installation from the command-line is recommended:

$ sudo dpkg -i logtalk_3.33.0-1_all.deb


Be sure to install a compatible Prolog compiler before running the Logtalk installer. Creates a Logtalk program group in the Start Menu with integration shortcuts for supported Prolog compilers and shortcuts for the accessing the Logtalk documentation. Can be used by both admin and non-admin users.

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Logtalk is also available as a Chocolatey package and can be installed or updated using the choco install logtalk and choco upgrade logtalk commands. Alternatively, on Windows 10 or Windows Server 2019, you can use the Windows Subsystem for Linux (WSL) and install Logtalk using one of the Linux installers listed in this page.

Installing on Windows 10 requires temporarily turning off Ransomware protection (in the Windows Defender Security Center preferences) if enabled as the Logtalk installer creates the the Logtalk user directory inside the Documents directory by default.

Automatically generated installers for the latest git versions can be download from AppVeyor.

SWI-Prolog packs

Logtalk is also available as a SWI-Prolog pack. The pack is handy for deployment but not ideal for development, however, as all the files in the distribution are buried in a relatively deep sub-directory. The pack can be easily installed typing the query pack_install(logtalk) at the top-level (use the pack_info(logtalk) query after installation to find the installation directory). Also available as a manual download:

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There’s also an experimental pack that encapsulates de Logtalk compiler and runtime in a logtalk module. This pack is only available as a manual download:

45131c4ac25bc30ede5c7743548bd9e0bda28ceaae067375be797bbabad52c3c (SHA-256)

Arch Linux package

Logtalk is also available as an Arch Linux package contributed by Ebrahim Azarisooreh.


HTML, ePub, PDF, and Texinfo versions of the Handbook (includes a tutorial, the User Manual, the Reference Manual, and the FAQ). Note that the HTML version is included in the source and binary packages.

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Docker images

Nightly and stable Docker images are available using selected backend Prolog compilers.

Older versions

Older releases are available here (but note that time stamps do not match the release dates due to all the moving of these files between servers along the years).


If you want to express you appreciation for Logtalk and help keep it a sustainable project, your sponsorship is much appreciated. Sponsorship monthly tiers start at a symbolic $2 per month to hopefully allow everyone to show their love and support for Logtalk.


Consider registering if you become a Logtalk user.