jBPM is a workflow engine for building business applications that automate business processes. You model processes as BPMN 2.0 flow charts, which a lightweight, extensible engine written in pure Java executes. It supports human tasks with assignment strategies, notifications and deadlines, business rule tasks that call DMN decisions and DRL rules evaluated by Drools, and long-running processes with durable state, timers, signals, message correlation and migration of running instances to a new process version. jBPM is delivered as software that development teams download and run themselves, alongside or inside their own Java applications.
jBPM is developed within Apache KIE, a project incubating at the Apache Software Foundation, and is published under the Apache License 2.0. Because the code is open and you operate it yourself, processes and the data they handle stay in the infrastructure you choose, including data centres in the EU, and no vendor-run cloud service is involved. For a European organisation, sovereignty then depends mainly on your own hosting and on the other components in your Java stack.