I had some troubles getting it started - required installation of commons-configuration-1.6.jar and juddi-client-3.0.0.jar into the deploy/riftsaw.sar/lib directory.
09:35:06,702 ERROR [AbstractKernelController] Error installing to Start: name=BPELEngine state=Create
09:37:12,327 ERROR [AbstractKernelController] Error installing to Start: name=BPELEngine state=Create
It cannot find the UDDI Registry package. This would happen if you don't have the JBossESB installed, since in that case you don't have jUDDIv3 installed either. So just set bpel.uddi.registration=false. You can find this property in the riftsaw.sar/bpel.property file.