Logtalk is a declarative object-oriented logic programming language that extends and leverages the Prolog language with a feature set suitable for programming in the large. Logtalk supports modern code encapsulation and code reuse mechanisms without compromising the declarative programming features of Prolog.
Logtalk is implemented as a trans-compiler in highly portable code and can use most modern and standards compliant Prolog implementations as a backend compiler.
As a multi-paradigm language, Logtalk includes support for both prototypes and classes, protocols (interfaces), categories (components and hot-patching), event-driven programming, coinduction, lambda expressions, and high-level multi-threading programming. Logtalk uses standard Prolog syntax with the addition of some operators and directives for a smooth learning path.
Logtalk is distributed under a commercial friendly license and includes full documentation, portable libraries, portable developer tools, and a large number of programming examples to help get you started.
The latest release of the Logtalk is always available at the URL:
At this address you can also find additional documentation and information about Logtalk.
Logtalk can be installed either from sources by running a few shell scripts
or by using one of the provided installers, depending on your operating
system. For manual installation, see the file INSTALL.md for detailed
instructions.
See the user manual for a description of the source files organization
and for using instructions (to read the user manual open the file
manuals/index.html with a web browser).
If you are upgrading from a previous Logtalk version, please check the
UPGRADING.md file for instructions on how to upgrade your
programs or your custom adapter files to run under this new version.
The file CUSTOMIZE.md provides detailed instructions for customizing the
Logtalk installation and working environment.
The file QUICK_START.md provides quick instructions for those of you in a hurry
to run Logtalk, provided that your favorite Prolog compiler is supported.
A quick and highly recommended introduction for users comfortable with Prolog and with general knowledge about object-oriented programming is available at Learn X in Y minutes website.
The HTML version of the Logtalk Handbook is included with the sources and can
be found in the manuals directory. It's also available online at the
Logtalk website.
The Handbook is the entry point for the Logtalk documentation. It includes the user manual, the reference manual, glossary, FAQ, the library overviews, plus the developer tools documentation.
The RELEASE_NOTES.md file contains descriptions of all
Logtalk updates since the first public version. Check it carefully if you
have been using a previous Logtalk version.
The API documentation for the core, library, tools, and contributions entities
is provided in XHTML format and can be found in the docs directory and
also available online on the Logtalk website.
Most directories include NOTES.md or NOTES.txt documentation files.
On POSIX systems, there's also a man page for most shell scripts.
A list of these scripts can be generated using the apropos logtalk command.
HTML versions of the man pages are also available
at the Logtalk website.
To register as a Logtalk user either use the registration form found at the Logtalk web site, https://logtalk.org/regform.html, or send an email message to:
with the following information:
email address, full name, organization, organization type (education, commercial, government, ...), prolog compilers used (optional), platforms (mac, pc, unix,...) (optional)
Support channels include:
Please consult https://logtalk.org/support.html for more information.
If you want to cite Logtalk in your publications, please consult the file
BIBLIOGRAPHY.bib for bibliographic references in BibTeX format.
Contributions are most welcome! See the CONTRIBUTING.md file
for details.
Logtalk is copyrighted by Paulo Moura. The Logtalk use and distribution
license can be found in the LICENSE.txt. Logtalk is available
under the Apache License 2.0. The copyright notice and license applies to
all files in this release unless otherwise explicitly stated. See the
NOTICE.txt for detailed copyright information.
Some files that are part of the Logtalk distribution are distributed using a different license and/or are copyrighted by a Logtalk contributor.
Some of the included examples are adaptations to Logtalk of Prolog examples found elsewhere (e.g. in manuals, tutorials, books, and public mailing list discussions). The copyright in the examples original code should be assumed to belong to the original authors.
Logtalk is a registered trademark of Paulo Moura.