Evaluating a Java Workflow engine

For the next version of our Net-Herald monitoring and controlling software I’m evaluating the different open source workflow solutions for Java. One can find long lists here and here. So far I’m tending to use OSWorkflow as it seems to be easily integrated into a non J2EE (yes, there are non J2EE Java applications) app. I’d like to use a workflow engine for the inner structure of the software. So that there is more after-deployment control what actions are taken whenever a signal from some observed device arrives. For instance the user wants to wait for a period of time until finally an alarm is fired. Or he wants to control a different device according to the received signal. Anyway, never mind :) Just loud thinking… Please leave your comments about this.