Most of the content about technical aspects of Information Technology is on the Development site, including information about specific business-rule products, rule engine design, computer languages, etc. Follow one of the the links listed below for more technically oriented content.
Updated Sept 29 2008:
See: Inference Engines on the Dev. site
It is important ot remember that term 'business rules technology' is often associated with business process managment. From the Wikipedia article for the Business Rule Approach:
From the Oracle Business Rules fact sheet:
The Oracle Business Rules components consist of a Rules engine; a Rules SDK, and a Rule Author Tool. The Oracle Rules Engine is written in Java. It is fast and efficient and well integrated with both Java and XML.