In this paper we introduce our multi metamodel process ontology (m3po), which is based on various existing reference models and languages from the workflow and choreography domain. This ontology allows the extraction of arbitrary choreography interface descriptions from arbitrary internal workflow models. We also report on an initial validation: we translate an IBM Websphere MQ Workflow model into the ology and then extract an Abstract BPEL model from the ontology. Categories and Subject Descriptors: H.4.1 [Information Systems Applications]: Office Automation--Workflow management General Terms: Languages