Drools is a Rete-based rules engine written in
Java, but able to run on Java and .Net. it is
designed to allow pluggeable language
implementations. Currently, rules can be written
in Java, Python, and Groovy. It also enables
domain-specific languages (DSLs) via XML using a
schema defined for your problem domain. DSLs
consist of XML elements and attributes that
represent the problem domain. An XML authoring
tool provides a semi-rapid development environment
with a drag and drop type interface based on the
provided schema.
