最近几年来，地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持，如城市管理、区划、环境整治等等，地理信息成为信息时代重要的组成部分之一； “数字地球”概念的提出，更进一步推动了作为其技术支撑的GIS的发展。 与此同时，一些学者致力于相关的理论研究，如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面，并且这两个方面构成了相互促进的发展过程。
A few years ago, Web services was not fast enough to generate interest. Because all major platforms can access Web through Web browsers, different platforms can interact with each other. To make these platforms work together, Web applications have been developed. Web applications are simple applications that run on Web. They are built around the Web browser standard and can be used by almost any browser on anyplatform. By using Web services, your application can publish features or messages to the world. Web services uses XML to encode and decode data and uses SOAP to transmit data through open protocols. Through Web services, your accounting department’s Win 2k server can connectto the IT vendor’s UNIX server. There are some features that are often used by different applications. So why develop them over and over again? Web services can provide application components as services, such as exchange rate conversion, weather forecasts, or even language translation. Ideally, there is only one best version of each application component, so that anyone can use it in their application. Web services helps solve the problem of working together by providing a way for different applications to link their data. By using Web services, you can exchange data between different applications and platforms. 5.3.1. The most important thing is to work together. ¶
5.3.2. Web services takes Web applications to another level. ¶
5.3.3. There are two types of applications for Web services ¶
5.3.4. Reusable application components ¶
5.3.5. Connect existing softwar ¶