As Web sites and intranets become larger and more complex, static HTML files hit their limits. In the first part of Web Application Development with PHP the authors explain PHP's advanced syntax like classes, recursive functions and variables. They present software development methodologies and coding conventions which are a must-know for industry quality products as well as to help making develop faster and more productive. This part covers also many standard algorithms for tree-structures, string sorting and searching. Part Two focuses on the concept of Web Applications (as opposed to single scripts) and gives much insight into user and session management, e-commerce systems, XML applications and WDDX.