Hi! ActiveBpel engine can be easily deployed on Apache Tomcat 5.x (I use 5.0.28 currently) by running install.sh (in linux os) in activebpel-5.0.2 package (which can be downloaded from http://www.activevos.com/community-open-source-engine-download.php). Note that CATALINA_HOME must be defined prior to installation.
You can deploy your .bpr archives into CATALINA_HOME/bpr folder. After starting tomcat, examine http://localhost:8080/BpelAdmin/deployed_processes.jsp where your deployed process should be in the list.