It is supported by a software system that includes an execution engine, a graphical editor and a worklist handler.
Subsequently, several organizations such as InterContinental Hotels Group, first:telecom and ATOS Worldline[2] have contributed to the initiative.
As a result, the original formal semantics of YAWL are defined as a labelled transition system and not in terms of Petri nets.
As a result, BPEL is supported by a significant number of tools (both proprietary and open-source) while YAWL has a single implementation at present.
In addition, the YAWL system comes with a default worklist service that supports several types of human task allocation and handling.