SWI-Prolog

SWI-Prolog
Original authorJan Wielemaker
DevelopersJan Wielemaker, Anjo Anjewierden, etc
Initial release1987 (1987)
Stable release
10.0.0  / 3 December 2025 (3 December 2025)
Written inC, Prolog
Operating systemCross-platform
Available inEnglish
TypeLogic programming
LicenseSimplified BSD, LGPL prior to version 7.3.33
Websitewww.swi-prolog.org 
Repository

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 was employed when he initiated the development of SWI-Prolog.