Review of the Main Technologies of WebGIS
万维网地理信息系统发展及前景

This paper introduces the main technologies for constructing a WebGIS, which is considered as an integration of Internet/Weg technologies and geographic information system. Compared with traditional GIS, many merits are showed in WebGIS. Recently many software producers have released WebGIS platform software all over the world. At the same time, many applications are built. The main technologies for WebGIS include CGI(Common Gateway Interface) method, Server Application Interface method, plug-in method, Java applets and ActiveX method. The Design models for WebGIS include 3-tie and multi-tie browser/server model. The most important feature for WebGIS is the interoperability. OpenGIS has been developing the interoperable model of WebGIS. A brief outlook for the main trends of WebGIS technologies and their applications are given. GML, Open Geographic Information System, distributed GIS, network based virtual geographic environment, mobile GIS would be the focus of GIS research and development in the future.