Bayesian Network tools in Java banner

Bayesian Network tools in Java (BNJ)

Latest release: v3.004 pre-alpha (21 July 2004)

Check out some version 3 screenshots!

[ Versión en Español (Spanish) | Chinese | Japanese ]

What is BNJ?

BNJ is an open-source suite of software tools for research and development using graphical models of probability. It is implemented in 100% pure Java and distributed under the GNU General Public License (GPL) by the Kansas State University Laboratory for Knowledge Discovery in Databases (KDD).

For information on the BNJ project and documentation, see the following pages.

    Yahoo! Groups - Join Now
[ LiveJournal main page ]
BNJ also has a community on the weblog (blogging) service LiveJournal: [ BNJ User info ]bayesnets

Now online: The BNJ Wiki at K-State

Who is on the BNJ Development Team?

How to Get BNJ

Want the latest source code and docs?
SourceForge Logo

Please remember to register BNJ online once you have downloaded it. Registration is free and takes only a few minutes.

How to Use BNJ

Software toolkit overview, presented at UAI-2003, by William H. Hsu and Roby Joehanes, Fri 08 Aug 2003 [ MS PowerPoint | PDF | HTML ]

User Tutorials

Read these if you just want to download and compile the basic utilities (the GUI-based Bayesian network editor and conversion tools, and the Inference Wizard and Learning Wizard tool).

Developer Tutorials

Read these if you want to build a new application that uses pre-implemented classes for representation of graphical models and inference and learning using them, or if you would like to: embed BNJ in your own Java-based application, modify or optimize an existing part of the BNJ core clases or other modules, or contribute a new module (class), package, or wizard.

Seminar on Graphical Models, KSU Math Department (09 Dec 2003)


BNJ Features and Development Status

BNJ development began in September, 1997 at the University of Illinois Department of Computer Science.
Development history of BNJ

BNJ version 2 has been in development since December, 2002. The final alpha release was v2.03a on 05 Nov 2003. v2 is now in feature-freeze. The first beta release, with a launcher executable for Windows and Linux, appeared on Sourceforge on Sun 16 May 2004. The final beta release (v2.2b) with minor optimizations is planned for Mon 31 May 2004, and an applications release with standalone, platform-specific executables (v2.3) is planned for Fri 11 Jun 2004.

The following new features are planned for BNJ v3 (4th quarter 2004):

BNJ User Community

As of Fri 21 May 2004, the BNJ source and binaries have been downloaded over 4500 times and over 130 offsite users have registered it.
Descriptive statistics about BNJ versions and users

Registering BNJ (optional)

To receive updates on new releases and to submit requests for documentation and new features, click here to register as a BNJ user or developer using the online form!

Your name and e-mail address are requested for major BNJ software development and release announcements only, and shall be kept confidential among BNJ developers.

If you have any questions, comments, or requests, please subscribe to the Yahoo! Group bndev.

Contributing to BNJ Development

We invite contributions from the user community in the following areas:

BNJ Terms (No-Warranty Disclaimer)



BNJ has been and continues to be developed through support from the following sponsoring agencies:



Corporate and Industrial Partners

Web Listings

The BNJ development team gratefully acknowledges the maintainers of the following sites for listing our package in their online directories or linking to this site:

If you have linked to our site on your Bayes nets page and would like a reciprocal link, please contact us.

Web Site Design

Mia Kalogjera

BNJ Development and Evaluation Team

Current Developers

Test Site Instructors


Past Developers

Past Affiliates

Relevant Publications and References


Page created: Thu 22 Aug 2002
Last updated: Wed 28 July 2004
William H. Hsu
BNJ Development Team