Best Open Source Business Rule Management System

Question

Does anyone know of a solid free and/or open source business rule management system. The organization I work for is developing increasingly more complex (business-wise) applications and it would be really nice to have a rule based system for saving, maintaining and allowing inter-relation of those business rules over time.

Edit: Additional point. The organization I work for is a .NET shop. Are the listed BRMS' focused on the Java programming language or are they language agnostic?

Thanks in advance, Jason

Answer 1

JBoss Rules/Drools: http://jboss.org/drools

EDIT: Drools is Java specific like what Jon said.

A quick search in Google produced the following:

• NxBRE
• SRE (Simple Rule Engine)

Source: http://csharp-source.net/open-source/rule-engines

I'm not sure how good are they. At least there are options.

Answer 2

I've used JBoss Rules/Drools in a past project. It's a forward chaining rules engine, based on Rete. It's but you need to be careful about when you load rules into working memory and when you fire them - there is obviously a performance overhead here. The biggest issue you will run into is in terms of building the rules - especially if you need to provide customers with an interface to build the rules. Building them programatically or reading in declarative based rules is fairly simple.

There are also some other frameworks you should consider as well:

• Jess - http://www.jessrules.com/
• OpenRules - http://openrules.com/
• JLisa - http://jlisa.sourceforge.net/

EDIT: Just to clarify. The rules engines above are very Java focused, and I'm not sure whether it's possible to use them from other languages easily.

There is an open source .NET implementation of Drools called Drools.net:

• http://droolsdotnet.codehaus.org/

See this discussion thread also:

http://stackoverflow.com/questions/6613/what-rule-engine-should-i-use

Answer 3

The .NET version of Drools is no longer actively maintained and is several major revs behind the Java Drools.