jlaunch Home Page


Java applications aren't standalone programs, but run by a Java interpreter. As a consequence, you can't configure a Java chess engine application directly as a engine under a chess GUI, but you have to configure the Java interpreter program java.exe as chess engine. Typical pathes for the Java interpreter program are:

What Is jlaunch ?

jlaunch is a native C program for Windows, that is similar to the Java JDK/JRE java.exe command. # The program uses the function JNI_CreateJavaVM of the Java Invocation API to create a JVM in the current process.

The function JNI_CreateJavaVM is loaded at runtime via LoadLibrary/GetProcAddress from the choosen jvm.dll file.

You can find more details about JNI (Java Native Interface) at


Copy the jlaunch program into the directory of your Java chess engine and create the proper jlaunch.properties file (see examples properties files below).

Why To Use jlaunch ?

Usually the chess GUIs use the directory, where the program is located as the working directory. In case of a Java chess engine application this would be under the JDK/JRE installation path and not where the files of the Java chess engine are located. With jlaunch located in the same directory, you can address other files (e.g. engine specific opening books) relative to the location of your Java chess engine application.

jlaunch Properties File jlaunch.properties

jlaunch reads the configuration data from the properties file jlaunch.properties. The format of lines in this file is:


Lines, that begin with a hash (#) in the first column are handled as comments.



Software Environment

jlaunch runs under Windows 2000 and Windows XP (other Windows versions aren't available for me so I don't know, whether jlaunch will run). The minimum needed Java version is Sun Java 1.2 but I strongly recommend to use either Java 1.3.1 or even better Java 1.4.2. The upcoming Java 1.5 is also suported.

Microsoft Java is more or less compatible to Sun Java 1.1.4 and therefore not supported.

jlaunch - Java Application Launcher Program


 jlaunch - Java launcher for Windows 2000/XP.

 Copyright (c) 2004 Manfred Rosenboom
 All rights reserved.

 This program is FREEWARE.

 You can redistribute it as long as you don't charge for it, or include
 it in a product which is distributed for profit. It is forbidden to
 change, split, copy, sell, disassemble or produce any changed form of
 this program release without the written permission of the author.

 This program is distributed in the hope that it will be useful, but
 WITHOUT ANY WARRANTY; without even the implied warranty of

Java Chess Engines

Ready to use property files for various Java chess engines.
Just rename the desired file to jlaunch.properties.

Cheetah 0.79aUCI / WB
Author Ralf Schäfer
Download private version
mainClassName cheetah.JTCheetah
classPath ./Cheetah_0_79a.jar
Properties Filecheetah.properties
Eden 0.0.5UCI
Author Nicolai Czempin
Download http://chess.czempin.de/
mainClassName de.czempin.chess.eden.Eden
classPath ./de.czempin.chess.eden_0.0.5.jar
Properties Fileeden.properties
OliThink 4.1.2WB
Author Oliver Brausch
Download http://home.arcor.de/dreamlike/
mainClassName de.dreamlike.olithink.OliThink
classPath ./olithink412.jar
Properties Fileolithink.properties
Pyotr Amateur 0.6WB
Author John Marountas
Download http://www.digichess.gr/pyotr/home.php?lang=en
mainClassName pyotr
classPath .
Properties Filepyotr.properties
Tiffany's 0.2WB
Author Bernhard von Gunten
Download http://tiffanys.sourceforge.net/
mainClassName ch.nostromo.tiffanys.Tiffanys
classPath ./Tiffanys.jar
Properties Filetiffanys.properties

Last updated: 10. June 2004, 11:47:15
Copyright Manfred Rosenboom marochess@yahoo.com