The concept of content delivery (also known as content distribution) is be­ coming increasingly important due to rapidly growing demands for efficient distribution and fast access of information in the Internet. Content delivery is very broad and comprehensive in that the contents for distribution cover a wide range of types with significantly different characteristics and performance concerns, including HTML documents, images, multimedia streams, database tables, and dynamically generated contents. Moreover, to facilitate ubiqui­ tous information access, the network architectures and hardware devices also vary widely. They range from broadband wired/fixed networks to bandwid- constrained wireless/mobile networks, and from powerful workstations/PCs to personal digital assistants (PDAs) and cellular phones with limited processing and display capabilities. All these levels of diversity are introducing numerous challenges on content delivery technologies. It is desirable to deliver contents in their best quality based on the nature of the contents, network connections and client devices. This book aims at providing a snapshot of the state-of-the-art research and development activities on web content delivery and laying the foundations for future web applications. The book focuses on four main areas: (1) web con­ tent delivery; (2) dynamic web content; (3) streaming media delivery; and (4) ubiquitous web access. It consists of 17 chapters written by leading experts in the field. The book is designed for a professional audience including academic researchers and industrial practitioners who are interested in the most recent research and development activities on web content delivery.