This unique text explores the core concepts central to the development of three tier, client server Web applications. A comprehensive introduction to the Internet and Web applications is followed by a brief refresher on HTML and CSS and an introduction to client side programming using JavaScript and browser objects. The heart of the book features a thorough exploration of concepts such as dynamically generated Web pages, session state, cookies, database support, and search capabilities. The concepts are implemented using Perl and MySQL. It includes a detailed coverage of ASP and PHP. As a capstone, a firm foundation in XML is provided through in depth coverage of XML basics, the DOM, and XSLT. This book: illustrates how to create three tier Web applications through hands on exercises and real world case studies; highlights important security issues throughout; uses Perl/CGI as the primary development environment; includes lessons on PHP and ASP as alternative development environments; and, introduces the XML language and how to use XML as a tool for building Web applications.