INTRODUCTION
Traditionally, geographic information systems were realized as monolithic and platform-dependent
applications (Wong et al., 2002). With development of Internet and World Wide Web, GISs have
evolved and adapted to this new environment (Shekhar et al., 2001). The “WebGIS” became a
synonym for Web information systems that provides a functionality of geographic information
systems on the Web through HTTP and HTML (Shanzhen et al., 2002).