Open ESB is a vibrant open source community that has created an enterprise-class, standards-based Enterprise Service Bus. The Open ESB community continues to collaborate with other communities including NetBeans and GlassFish to create the most comprehensive, mature and fully open source integration platform available in the market today. Event processing addresses many critical problems in this space and is becoming an important part of any ESB offering. Open ESB provides event processing capabilities and visual tooling to deliver applications using an Event-Driven Architecture. You can find more information on event processing capabilities here -  https://open-esb.dev.java.net/IEPSE.html.