[2-7] Free Logic Programming Systems

ALF:
   ALF (Algebraic Logic Functional programming language) is a
   language which combines functional and logic programming techniques.
   The foundation of ALF is Horn clause logic with equality which
   consists of predicates and Horn clauses for logic programming, and
   functions and equations for functional programming.  The abstract
   machine is based on the Warren Abstract Machine (WAM) with several
   extensions to implement narrowing and rewriting.     In the current
   implementation programs of this abstract machine are executed by an
   emulator written in C. It is available by anonymous ftp from
      ftp.germany.eu.net:/pub/programming/languages/LogicFunctional/
   (aka simpson.germany.eu.net) as the files alf_*.zoo
   (Documentation, C sources for the emulator, the preprocessor and the
   compiler). For further information, contact Rudolf Opalla
   <opalla@julien.informatik.uni-dortmund.de>.

CORAL:
   CORAL is a deductive database/logic programming system developed at
   the University of Wisconsin-Madison. It is a declarative language
   based on Horn-clause rules with extensions like SQL's group-by and
   aggregation operators, and uses a Prolog-like syntax.

   CORAL is available via anonymous ftp from ftp.cs.wisc.edu:/coral/.  The
   distribution includes source code compatible with AT&T C++ Version 2.0
   or later, executables for Decstations and SUN 4s, the CORAL User
   Manual, and some related papers containing a language overview and
   implementation details.  (A version of the source code compatible with
   GNU g++ will be available shortly.) For more information, contact
   Raghu Ramakrishnan, <raghu@ricotta.cs.wisc.edu>.

Lolli:
   Lolli is an interpreter for logic programming based on linear logic
   principles. Lolli, named for the linear logic implication operator
   "-o" called lollipop, is a full implementation of the language
   described in the paper "Logic Programming in a Fragment of
   Intuitionistic Linear Logic" (Josh Hodas & Dale Miller, to appear in
   Information and Computation), though it differs a bit in syntax, and
   has several built-in extra-logical predicates and operators. Lolli is
   available by anonymous ftp from 
      ftp.cis.upenn.edu:/pub/Lolli/Lolli-07.tar.Z 
   This distribution includes full ML source, along with a Makefile, as well
   as several background papers and a collection of example programs. For
   those who do not have SML-NJ at their site, the authors hope to
   provide pre-built binaries for a variety of architectures. These
   binaries can be found on 
      ftp.cis.upenn.edu:/pub/Lolli/binaries/
   At present Sparc and NeXT binaries are available.  If you compile
   lolli on a new architecture, please contact Josh Hodas at
   <hodas@saul.cis.upenn.edu> so that he can make your binary available.

See also LIFE, SLG, and XSB in [2-1], BeBOP in [2-3], and Oz in [2-5].