Complex event processing engines are a natural fit for event driven platforms like Mule. Native CEP support has been available in Mule since version 3.2 by way of the Drools Module. The Esper Module now offers an alternate way to leverage CEP in your integration applications. Esper is a robust, performant, open source, complex event processing engine. Let’s take a look at how to use Esper with Mule and then see how it compares to Drools’ CEP support.