Service-Oriented Software Engineering (SOSE) presents new challenges; in particular, how to promote interoperability and cooperation among loosely-coupled service resources. This is critical for service resource sharing and for implementing on-demand services. This paper discusses key technologies of service virtualization, including encapsulation of service interoperability (for available resources); ontology-based Role, Goal, Process, and Service (RGPS) metamodeling (for interoperable aggregation and organization of virtualization services); registration and repository management of Metamodel Framework for Interoperability (MFI) (for virtualization service management); and virtualization service ontology and its represented association with RGPS. Latest progress of the MFI and ISO standards is also discussed.