SWI-Prolog Logic Programming

SWI-Prolog is a comprehensive, free and open-source implementation of the Prolog programming language, widely used in research, education, and commercial applications. Developed by Jan Wielemaker at the University of Amsterdam (SWI) starting in 1987, SWI-Prolog has become the most popular Prolog implementation with a large community and extensive library ecosystem. Key features: ISO Prolog standard compliance with numerous extensions including tabling, constraints (CLP), coroutining, and rational trees. Multi-threaded execution with shared data and message passing for concurrent and parallel Prolog applications. Constraint Logic Programming (CLP) libraries including CLP(FD) for finite domains, CLP(B) for boolean domains, and CLP(Q,R) for rational and real arithmetic, for solving combinatorial optimization problems. Tabling (memoization) for efficient handling of recursive predicates, enabling left recursion and dynamic programming. Web framework (SWISH and HTTP server) for building web applications and providing browser-based interactive Prolog environments. RDF and Semantic Web libraries for parsing, querying (SPARQL), and reasoning with RDF, RDFS, and OWL ontologies. C and C++ foreign language interface for embedding Prolog in native applications or extending with C libraries. Just-in-time term hashing and indexing for fast clause lookup. Unicode support throughout the system. PceProlog and XPCE graphical toolkit for building native GUI applications. PlUnit testing framework for unit testing Prolog code. Pengo natural language processing toolkit. SWISH web-based IDE enabling collaborative Prolog development in the browser. Used in artificial intelligence, expert systems, natural language processing, semantic web, and automated reasoning. Cross-platform on Windows, macOS, and Linux.