In this paper, we present a Web-based framework for interactive Sign Language using virtual signing agents. The main feature of this framework is that it is a full DOM-Integrated architecture. Firstly, we discuss the advantages and the constraints raised by the implementation of proper interactive Virtual Signers within this full DOM-integrated approach. Secondly, we discuss an experimental study about Web-based Virtual Signers that take advantage of the specific interactivity provided by our framework. This study deals with a structure of Sign Language utterances that requires dynamic handling of spatiotemporal variability and coarticulation postures in the sign generation phase.