JavaLog
Experimental Prolog interpreter in Java, mixing Logic and OO paradigms.
Jinni 2000 (Java INference Engine and Networked In
A fast multi-threaded, networking and GUI enabled Prolog compiler, extensible through a Reflection based Java interface.
JIP
Java Internet Prolog is a Prolog Java-compatible interpreter. JDK1.1- and Edinburgh Prolog-compliant this Prolog version allows code written in Prolog to be run in any Java applet or application and Java methods to be called in any Prolog code.
JLog
A Prolog interpreter, written in Java, that is well suited for educational purposes. It works as both an application and as an applet.
jProlog
Experimental Prolog to Java compiler, running on JDK 1.0.2 and higher.
MINERVA
Implementation of ISO Prolog in 100% Java. Extensible with any Java class. Callable as servlet, applet, standalone, or Java class library. Includes XML parser and generator. [Commercial]
Prolog+CG
Java implementation of Prolog plus the Conceptual Graphs of John Sowa. Object oriented extensions also included. [Open source, LGPL]
tuProlog
A Java-based light-weight Prolog for Internet applications and infrastructures, developed at DEIS - Universita' di Bologna. [Free for non-commercial use]
W-Prolog
This simple interpreter for a Prolog-like language is written in Java. Although not fast the implementation is extremely portable and can be run as an applet under Java-capable web browsers.