Free/Shareware Prolog implementations

lang/prolog/impl/prolog/

   adapdpro/  ADA PD Prolog: Slow Prolog for MS-DOS systems.
   aquarius/  Aquarius Prolog: Information about Aquarius 
              Prolog, a free (with license) high-performance 
              portable implementation of Prolog.
   beta_pl/   Beta Prolog: Fast and portable Prolog emulator 
              and compiler.
   bin_pl/    BinProlog: Fast, small, and portable Prolog 
              compiler.
   boiz_pl/   Prolog interpreters from Boizumault's book
   eclipse/   ECLiPSe: ECRC Logic Programming System
   elp/       eLP: Ergo Lambda Prolog
   eslpdpro/  ESL Prolog-2 (PD Version): Good performance 
              public domain (limited) version of a Prolog for 
              MS-DOS systems.
   frolic/    FROLIC: Prolog implemented in Common Lisp and 
              integrated with the FROBS knowledge 
              representation system
   icp/       ICP: IC-Prolog ][, a multi-threaded Prolog 
              implementation suitable for distributed 
              applications.
   jbprolog/  JB-Prolog: Fast Prolog Demo System for the 
              Macintosh
   lmprolog/  LM-Prolog: Prolog implemented in ZetaLisp for 
              Lisp Machines.
   lp/        LP: Lambda Prolog
   mac_pl/    MacProlog: Demonstration version of LPA 
              MacProlog.
   op/        Open Prolog: Prolog interpreter for the Apple 
              Macintosh
   pdprolog/  A.D.A. PD Prolog: A slow Prolog for MS-DOS 
              systems.
   pm/        Prolog/Mali: Compiler for higher-order Lambda 
              Prolog
   ppicl/     FJ PPiCL: Portable Prolog in Common Lisp from 
              Japan
   prolog2r/  PrologIIR: Un interpreteur de Prolog.
   prolog68/  Prolog68: WAM-based Prolog for Atari ST and TT 
              computers.
   sbprolog/  SB-Prolog: Stony Brook Prolog
   schelog/   Schelog: Embedding of Prolog in Scheme
   scm_pl/    Prolog implemented in Scheme, with interval 
              arithmetic.
   sicstus/   SICStus: Information about SICStus Prolog for 
              Unix.
   swi_pl/    SWI Prolog: Fairly complete Edinburgh-style 
              Prolog.
   tricia/    Tricia Prolog: Edinburgh-style Prolog for 
              Macintosh (and UNIX).
   unsw_pl/   UNSW Prolog: Prolog for the Amiga
   wamcc/     WAMCC: WAM-based Prolog to C compiler
   xsb/       XSB Prolog: Prolog extended with OLDT (tabling) 
              and Hilog terms.