This document discusses a system architecture for web service based GIS. The system is designed to provide hosted spatial data and GIS functionality through web services to allow for integration with various customized application systems. The web services can be used to perform basic geo-processing tasks like address matching, map display, and routing without needing to maintain the underlying geographical data. The system implements open standards like WMS, WFS, and GML. It has a multi-layer architecture with interfaces for web services, servlets/JSPs, and GIS APIs built on a J2EE framework. The system provides a distributed platform for sharing geospatial information to support applications like transportation planning.