PHP is an open source, server-side HTML-embedded web-scripting language for creating dynamic web pages. Outside of being browser-independent, it offers a simple and universal cross-platform solution for e-commerce, complex web, and database-driven applications. Professional PHP4 will show you exactly how to create state of the art web applications that scale well, utilize databases optimally, and connect to a back-end network using a multi-tiered approach. This book also aims at teaching PHP by coding - among other things - FTP clients, e-mail clients, some advanced data structures, session management, and secure programming. What does this book cover? The whys and wherefores of PHP4 PHP installation on *nix, Windows, and MacOS X Sessions and cookies, coding FTP clients, network-related function calls, and directory services PHP support for LDAP Multi-tiered development using PHP PHP's interaction with XML PHP with MySQL PHP with PostgreSQL and ODBC Securing, optimizing, and internationalizing PHP applications PHP extension libraries A real world employee directory, an online library application, and a GTK interface to the application Case studies on a user privilege system and a multi-tiered WML-based shopping cart