| Synchronous collaborative environments can provide an identical visual and operable working area among geographically separated participants. There are two basic approaches for providing a shared workspace. The first one, collaborative-aware approach, relies on the development of collaborative-aware applications that directly support multiple simultaneously active user inputs and synchronization of outputs to all participants. The second one, collaborative-unaware approach, introduces some intermediate layers between existing single-user applications and the underlying window management system. These layers enable single-user applications to be shared transparently. In order to reuse the large amount of existing single-user applications, most users choose the collaborative-unaware approach. However, to build collaborative-unaware systems to share single-user applications transparently is a great challenge.; This thesis describes the design and implementation of some transparent synchronous collaborative tools. They are: (1) the latecomer support for Java applications, Java applets and JMF players; (2) the client synchronization to minimize data transmission latency; (3) the light-weight multi-session support to let different collaboration groups work at the same time and (4) the collaborative VRML viewer to integrate the blaxxun3D VRML viewer with collaboration systems. These tools optimize existing transparent synchronous collaboration systems and make them more realistic, more complete and more generic. |
