From Wikipedia, the free encyclopedia
Jump to: navigation, search
Original author(s) Jan Wielemaker
Developer(s) Jan Wielemaker, Anjo Anjewierden, etc
Initial release 1987; 30 years ago (1987)
Stable release
7.4.2 / 18 April 2017; 4 months ago (2017-04-18)
Preview release
7.5.13 / 18 August 2017; 3 days ago (2017-08-18)
Development status Actual
Written in C, Prolog
Operating system Cross-platform
Available in English
Type Logic programming
License Simplified BSD, LGPL prior to version 7.3.33
Website swi-prolog.org

SWI-Prolog is a free implementation of the programming language Prolog, commonly used for teaching and semantic web applications. It has a rich set of features, libraries for constraint logic programming, multithreading, unit testing, GUI, interfacing to Java, ODBC and others, literate programming, a web server, SGML, RDF, RDFS, developer tools (including an IDE with a GUI debugger and GUI profiler), and extensive documentation.

SWI-Prolog runs on Unix, Windows, Macintosh and Linux platforms.

SWI-Prolog has been under continuous development since 1987. Its main author is Jan Wielemaker.

The name SWI is derived from Sociaal-Wetenschappelijke Informatica ("Social Science Informatics"), the former name of the group at the University of Amsterdam, where Wielemaker is employed. The name of this group has changed to HCS (Human-Computer Studies).

Web Framework[edit]

SWI-Prolog installs with a web framework based on definite clause grammars.[1]

Distributed Computing[edit]

Through the Pengines system SWI-Prolog queries may be distributed over several servers and web pages.[2]


XPCE is a platform independent object oriented[3] GUI toolkit for SWI-Prolog, Lisp and other interactive and dynamically typed languages. Although XPCE was designed to be language-independent, it has gained popularity most with Prolog. The development XPCE graphic toolkit started in 1987, together with SWI-Prolog.

It supports buttons, menus, sliders, tabs and other basic GUI widgets. XPCE is available for all platforms supported by SWI-Prolog.


PceEmacs is a SWI-Prolog builtin editor. PceEmacs is an Emacs clone implemented in Prolog (and XPCE). It supports proper indentation, syntax highlighting, full syntax checking by calling the SWI-Prolog parser, warning for singleton variables and finding predicate definitions based on the source-information from the Prolog database.


JPL is a bidirectional interface between Java and Prolog.[4] It requires both SWI-Prolog and Java SDK.[5] It is installed as a part of SWI-Prolog.

See also[edit]


  1. ^ Creating Web Applications in SWI-Prolog
  2. ^ Wielemaker, Jan; Lager, Torbjorn (14 May 2014). "Pengines: WebLogic Programming Made Easy". Theory and Practice of Logic Programming. 14 (special issue 4-5): 539–552. doi:10.1017/S1471068414000192. 
  3. ^ Programming in XPCE/Prolog
  4. ^ http://www.swi-prolog.org/packages/jpl/
  5. ^ http://www.swi-prolog.org/packages/jpl/installation.html

External links[edit]