- Internet is a place nowadays where interoperating services are offered which can be integrated or mashed up in order to fulfill user demands. This paper proposes a way to offer videoconference as a web service over an interface which can be used by third parties to enrich their applications. This interface includes a security mechanism supporting delegated authorization to allow integration into third party's environments. Via this interface virtual rooms are provided where users can collaborate with audio, video, shared applications, 1M, etc. An implementation of these concepts is described, including performance figures and validation results. We would finally like to stress that this architecture has been defined to support a scalable cloud computing service over the Internet. Cloud computing; Videoconferencing; Web; Real-Time Collaboration; SOA; ROA.