Jess is a rule engine and scripting environment for the Java platform. JSR 94 is a developing JCP standard for interfacing rule engines to Java software. The reference implementation of JSR 94 is a driver for Jess; with it, you can connect Jess to Java software. This article shows you how to apply the javax.rules API to access Jess from your J2EE or J2SE applications.

Read Jess and the javax.rules API

Jess is not available under any free license. The license agreement on the Jess sites says:

"Note: Jess is not licensed under the GPL, the LPGL, the BSD license, or any other free software or open source license. Redistribution of the Jess source code under any free software or open source license is prohibited under this agreement."

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For a list of open source rules based engines, go here:

http://www.manageability.org/blog/stuff/rule_engines

It lists 9 packages all written in 100% pure java.

Jess is commercial software, like its main competitors (Weblogic, ILOG JRules, Blaze Advisor). The way Jess is actually licensed is more generous than most. Academic and government users can get a full license for free, and all licensees get full source code. The commercial support is excellent. Anyway, I'm a happy user. Don't discount Jess because it's not free; in this case you definitely get what you pay for.

ILOG is very good, very mature. I evaluated it too some time ago via an eval download and I must say, their API and documentation are excellent. The bundled tomcat server and webapp in the eval helped clarify the concepts and working a lot. It is very obvious that some really smart people created this piece of software.

Now all we need is a workflow API and we are done.

besides jess language is a script that has nothing to do with the business. Weblogic, ILOG JRules, Blaze Advisor etc are also complex because they try to do many things at the same time, not just rules. Rulesharp is somewhat easier because it is pure rules, and the rule logic in in database or xml, not in some script. anyways, just my thought randy

Yes, I'm a vendor of another Java business rules product (Fair Isaac Blaze Advisor). I don't want anyone accusing me of hiding that farther down the page!

I just thought readers should be aware that other implementations of the JSR-94 Java rule engine interface standard are certainly available outside of Jess. Blaze Advisor, for instance, introduced an out of the box deployment for JSR-94 with the first public review specification in October 2002. Our implementation and others were demonstrated in a conference session this June at Java One.

Mr. Friedman-Hill's article is excellent... just a wee bit restrictive on alternatives for the buying public.

Thanks for the soapbox. We now return you to your discussions of the article content.

--Ken Molay
  Fair Isaac Corporation

I was looking into Java rule based engines a while ago which is when I saw the Blaze Adviser product for the first time. Since there is a post about it from what appears like an employee, I'd like to express my BIG DISAPPOINTMENT with your company for not letting developers download your product. That sucks! Look at any self respecting Java vendor, they let you evaluate the product. How do you expect consultants to recommend your product and companies to buy it if you make us jump through hoops and beg for a download?

I would certainly try to find an alternative that I can evaluate. Hopefully one day your company will change its policy, the white paper looked pretty good.

This book is simple printout of Manual.pdf available on JESS website. At least has same content.

The Jess language tutorial part of "Jess in Action" does have some text in common with the manual, although it looks like it's been revised a lot. But most of the book is a set of nice tutorials on building large applications with Jess, and none of this material is available elsewhere.

Can I use Fair Isaac Blaze Advisor to improve my FICO score?

Last year I developed 2 projects utilizing rules system. Every time my choice was iLog. The reason is I was able to evaluate iLog before in my spare time. same as JESS.
I tried to get eval lic. for Blaze, but your sales simply hanged-up phone, after hearing that I am a consultante and don't want to buy it immediately.

--Maxim Ragozin

Maxim,

I had the same problem with iLog Team. I'm trying to eval some rule engines for academic MSc study and for a commercial project in a Brazilian bank. But they don´t answer my mail or phones.

Glauber Gallego

I am trying to get in touch with ILog without success. Can you point me to someone who can help me with pricing ?

Thanks in advance.

You can obtain more information about jess from:

Jess in Action: Rule-Based Systems in Java
by Ernest Friedman-Hill

Paperback: 480 pages ; Dimensions (in inches): 1.08 x 9.18 x 7.40
Publisher: Manning Publications Company; (July 2003)
ISBN: 1930110898
Average Customer Review: Based on 3 reviews. Write a review.
Amazon.com Sales Rank: 5,845


Cheers
founder_chen
Co-founder www.huihoo.org

We evaluated several currently available business rules engines including ILOG's JRules and picked one developed by the Haley Enterprise. It is a nice piece of software. Tools management package called Authorete provides natural language support which is unmatched by any other tool, the run-time engine is deployed as part of your application. It has some nice features including lazy instantiation of the ruleset, dynamic loading, multithreding, and more. We deployed the knowledge base on the Weblogic 7 and 8 as a part of the J2EE system and it worked nicely. Deployment was very easy. Another good thing about this tool is that almost eveything that you need to do in terms of business ruless definition could be done inside the Authorete without using the scripting rules language. Unfortunately it's not the case with others. For instance with ILOG's product, in order to implement even simple looping through the collection you have to use their proprietory rules language.
For those who are interested I'd be glad to tell you more, or you can go directly to their web site www.haley.com.

P.S. I am not affiliated with this company (just in case)

Yeah, right.. ;)

I am affiliated with this company :) and I think you can tell if you got the best apple if you compare it with all the other apples. Always make sure you really want an apple and make sure not to compare it with oranges :) anyways, I think Rulesharp is best and time will tell: jrules , blaze , haley authority , jess , etc are complicated platforms. Rulesharp is pure rules in java,xml,sql,html, nothing more nothing less. Randy www.rulesharp.com

Thanks in advance

Dear Mike Velikovich,
Would really appreciate if you could share the findings of the comparative study.

Regards
Siddhartha SenGupta
Sid_tilin@yahoo.com

Does anybody have any experience with Yasu Technologies QuickRules Rules Engine?
http://www.yasutech.com/products/quickrules/index_SE.htm