There are several approaches on how to model a business process in software applications (BPM software). For instance, a processes can be described in BPMN, EPC, IDEF0, SOMF, etc.
Additionally, different process execution languages such as BPEL, RPC, Wf-XML are available.
If I were to develop software for the BPM-market, which standards should I implement or focus on? Which standards are most suitable if my BPM software was going to be implemented in my client's IT-System?