Higson.io - Hyperon is a BRMS, that was created with very large decisions and hyper-performance in mind. It stands out with the concept of the business domain which organizes the whole configuration in easy to manage way.
OptaPlanner - Mathematical optimization software
Vroom - Vehicle Routing Open-source Optimization Machine
Simple Rule Engine - DotNet simple BRMS XML rule engine
Autoly - Autoly turns auto trading into a highly entertaining experience using AI technology to make buyer, seller, and owners’ journeys more fun and less stressful.
Drools - Drools introduces the Business Logic integration Platform which provides a unified and integrated platform for Rules, Workflow and Event Processing.