Prof. Huang Bo from Department of Geography & Resources Management of Chinese University of Hong Kong, and Prof. Lin Hui from the Institute of Space and Earth Information Science (ISEIS) of Chinese University of Hong Kong visited the Hydro-Lab on May 26, 2007. Prof. Huang gave a talk on some frontiers in the field of geographical information system (GIS) research and application, including spatial-temporal object modelling, spatial optimization, visualization, and location-based services. Prof. Lin gave a very informative review on the process of geographic language evolution, from the map through GIS to virtual geographic environment.