Drools is a Business Rules Management System (BRMS) solution. It provides a core Business Rules Engine (BRE), a web authoring and rules management application (Drools Workbench), full runtime support for Decision Model and Notation (DMN) models at Conformance level 3 and an Eclipse IDE plugin for core development.
Drools is open source software, released under the Apache Software License. It is written in 100% pure Java™, runs on any JVM and is available in the Maven Central repository too.
More information can be found on the following links: