I am working to make an survey to choose a workflow  engine for our
application hesitate to choose an standard  language BPEL vs XPDL
as you know BPEL is suitable for web services and used widely in work
by
famous corps like Microsoft , Oracle , SAP , IBM , sun , .. ..
but Xpdl is standardized by WFMC and OMG ?
is anybody expert in workflow engines that can recommend  good
criteria for choosing a best alternatives ?
what about an open  source implementation in java ?