erver model, each application has its own client program and had to be separately installed on the client machine. Only after the client applica- tion is installed on the machine will the user interface be available. Any upgrade of client application would require an upgrade of solution running on individual user workstation also. This resulted in a huge maintenance cost and decreased produc- tivity. Also with the wide spread use of Internet, there was an increased demand for making applications available anytime and anywhere. Web Communication The advantage of Web applications is that it uses a generic client application. Web documents are written in a standard format such as HTML that can be pre- sented on any Web browser and does not require a specific client application. So any change in the server will not require an upgrade on the client workstation. During the session, the Web browser interprets and displays the pages and acts as the universal client for any Web application. Most of the current EMS, NMS, and OSS/BSS applications are Web based. The intent of this chapter is to introduce the reader to Web application development, SO that the fundamentals can be supple- mented with additional reading to develop scalable Web-based operation support solutions. Additional Reading 1. Ralph F. Grove. Web-Based Application Development. Sudbury, MA: Jones & Bartlett Publishers, 2009. 2. Leon Shklar and Rich Rosen. Web Application Architecture: Principles, Protocols and Practices. 2nd ed. New York: Wiley, 2009. Susan Fowler and Victor Stanwick. Web Application Design Handbook: Best Practices for Web-Based Software. San Francisco, CA: Morgan Kaufmann, 2004. 4. Ralph Moseley. Developing Web Applications. New York: Wiley, 2007. 5. Wendy Chisholm and Matt May. Universal Design for Web Applications: Web Applications That Reach Everyone. California: O'Reilly Media, Inc., 2008. Chapter 29 Mail Communication This chapter is about the mail communication. It introduces the reader to the concept of writing programs for mail ser