Brain Aid Prolog

Based on Edinburgh Prolog and extended with object-oriented mechanisms, this Berkeley-style open-source system has a compiler written in Prolog and generating Transputer assembly code.
http://www.comnets.rwth-aachen.de/~ost/private.html

ALS Prolog

Applied Logic Systems, Inc. provides a full-featured, Edinburgh-style Prolog compiler with GUI tools for Unix, Windows and Macintosh platforms.
http://www.als.com/

Amzi! Prolog + Logic Server

This extensible Prolog version runs under Windows, Linux, Solaris and HP/UX, supporting development of client and server applications embeddable in the web, C/C++, Java, Delphi, Visual Basic and other environments. An IDE is available for Windows along w
http://www.amzi.com/

Aquarius Prolog 1.0

The compiler for this open-source version developed at UCB is built around the Berkeley Abstract Machine, a finer-grained rendition of WAM. An interpreter provided for program development is written in Prolog.
http://www.info.ucl.ac.be/people/PVR/aquarius.html

Logic Programming Associates

WIN-PROLOG, DOS-PROLOG, MacProlog32 compilers. Products range from Prolog++ an OOPs extension, flex an expert system toolkit, and various web based technologies. [Commercial]
http://www.lpa.co.uk/ind_pro.htm

BinProlog

BinNet Corporation offers a high-performance, robust Prolog system able to generate C/C++ code and standalone executables and providing high-level networking along with secure internet programming integrated with rule-based reasoning components.
http://www.binnetcorp.com/BinProlog/

B-Prolog

Free, compact, full CLP system that runs Prolog and CLP(FD) programs. Emulator based, performance similar to SICStus-Prolog. Runs on: FreeBSD, Linux, Solaris, SunOS, Unix, Windows 9x/NT/2000.
http://www.sci.brooklyn.cuny.edu/~zhou/bprolog.html

Ciao Prolog Development System

Full ISO-Prolog compliant system, modular design allows language restriction and extension. Descriptions, contacts, mail lists, downloads. [Open Source, GPL]
http://clip.dia.fi.upm.es/Software/Ciao/

cu-Prolog

Constraint Unification Prolog (CUP), developed by Institute for New Generation Computer Technology (ICOT), Japan. Originally written in C with Unix, MacCup for Macintosh, DJCup for MS-DOS. Free software. FTP site.
ftp://ftp.icot.or.jp/pub/cuprolog/

SWI-Prolog

Stable and free standard Prolog implementation. Targeted primarily at research and education. Windows, Linux and Unix versions available. Comes with a visual debugger and a GUI environment.
http://www.swi-prolog.org/

Arity/Prolog

With a compiler and interpreter written in Prolog, C and assembly language and representing a superset of Edinburgh Prolog, a programming environment is offered for Windows/NT.
http://www.arity.com/www.pl/products/ap.htm

GNU Prolog

This compiler accepts Prolog + constraint programs and produces native binaries. The obtained executable is subsequently stand-alone. The size of this executable can be quite small since GNU Prolog can avoid linking the code of most unused built-in predic
http://pauillac.inria.fr/~diaz/gnu-prolog/

NU-Prolog

The successor of MU-Prolog, this compiled Prolog system designed and implemented in the mid-80's as a 'purer' logic solution, interfaces with UNIFY databases and is available under an academic license.
http://www.cs.mu.oz.au/~lee/src/nuprolog/

Palm Toy Language

A toy PROLOG interpreter for Palm. First PROLOG in PalmPilot.
http://www.geocities.com/willowfung/

IF/Prolog

A Prolog implementation for use in industrial and commercial environments. It complies with the ISO Prolog standard and runs on UNIX and MS-Windows environments. IF/Prolog has a rich set of interfaces to standard software components and an additional Cons
http://www.ifcomputer.de/Products/Prolog/

Quintus Prolog

The Swedish Institute for Computer Science's implementation of Prolog for UNIX and PC platforms is embeddable, integrable and commercial-strength.
http://www.sics.se/isl/quintus/

SICStus Prolog 3

This ISO-conformant performance-oriented Prolog development system also features interfaces with C/C++, Java and ODBC-compliant DBMS's and an OOP extension.
http://www.sics.se/sicstus.html

Strawberry Prolog

This Prolog compiler for Windows 95/98/NT and Unix/Linux supports OLE and Prolog CGI Scripts. Strawberry Prolog is suitable for client-server applications and has unique debugging facilities.
http://www.dobrev.com/

Reform Prolog

Recursion-parallel Single Program, Multiple Data (SPMD) implementation; assumes one sequential worker and arbitrary, fixed number parallel workers, each worker is process, can have more workers than processors. Successor: High Performance Erlang. [Open So
http://user.it.uu.se/~thomasl/reform.html

Trinc-Prolog, an object oriented prolog for Windows

Trinc-Prolog is a new development tool for the prolog language. Trinc-Prolog supports the ISO Prolog standard and has extended the prolog language with innovative object oriented features. TPWIN,an OO class library is available to develop Windows applicat
http://www.trinc-prolog.com/

Logtalk

An object-oriented extension to the Prolog programming language. It integrates logic programming with object-oriented and event-driven programming. Compatible with most Prolog compilers. [Open source]
http://www.logtalk.org/

Visual Prolog

A full-featured programming environment is offered with all the facilities necessary to write mission-critical, commercial-grade applications. A freeware version is available.
http://www.visual-prolog.com/

K-Prolog

This is the English Online Manual for this Japanese implementation of Prolog for Solaris, HP-UX and 32-bit Windows environments.
http://prolog.isac.co.jp/doc/en/

The YAP Prolog System

The University of Porto's Edinburgh-style, WAM-based Prolog engine is available on 32-bit machines running Sun and Linux and 64-bit Alphas running OSF UNIX and Linux. An open-source policy is being implemented with regard to distribution.
http://www.ncc.up.pt/~vsc/Yap/

IC-Prolog

As part of Imperial College's Logic Programming Group Software Products, this Edinburgh-style, WAM-based version provides multiple threading, an object-oriented layer, TCP interfacing and other features.
http://www-lp.doc.ic.ac.uk/software.html

EZY Prolog

A typed prolog interpreter, compatible with Visual Prolog, powrefull syntax checker with flow pattern analyser, GUI designer for declarative GUI, built-in functionality for ODBC, Winsock, regular expressions, text parsing, XML processing, HTML formatted o
http://www.ezy-software.com/ezyprolog/Prolog_Inference_Engine/ezy_prolog_overview.htm

ProFIT

Prolog with Features Inheritance, and Templates: Prolog extension with sorted feature structures (including multi-dimensional inheritance), finite domains, feature search, cyclic terms, templates.
http://www.coli.uni-sb.de/~erbach/formal/profit/profit.html

CMU Free/Shareware Prolog

CMU's AI repository offers a collection of Prolog implementations.
http://www-2.cs.cmu.edu/afs/cs/project/ai-repository/ai/lang/prolog/impl/prolog/0.html

INRIA wamcc

Predecessor to GNU Prolog. Compiles Prolog via GCC 2.x
ftp://ftp.inria.fr/INRIA/Projects/contraintes/wamcc/

Babol Prolog

Prolog WAM-based compiler (console). Still in development phase. Manual, examples, windows console demo, boot-file download.
http://zamek.gda.pl/~budyn/

Qu-Prolog

The Software Verification Research Centre (Univ. of Queensland) extended version of Prolog currently released under Linux and Solaris is designed primarily as a prototyping language and tactic language for theorem provers, including support for efficient
http://www.itee.uq.edu.au/~pjr/HomePages/QuPrologHome.html