To remain competitive, enterprises have to integrate their business processes with their customers, suppliers, and business partners. Increasing collaboration includes not only a global multi-national enterprise, but also an organization with its relationship to and business processes with its business partners. Standards and technologies permit business partners to exchange information, collaborate, and carry out business transactions in a pervasive Web environment. There is however still very limited research activity on modeling multi-party business collaboration underlying semantics. In this chapter, we demonstrate that an in-house business process has been gradually outsourced to third parties and analyze how task delegations cause commitments between multiple business parties. Finally, we provide process semantics for modeling multi-party collaborations.