This book was written to introduce you to the features and capabilities that ASP.NET 4 offers, as well as to give you an explanation of the foundation that ASP.NET provides. We assume you have a general understanding of Web technologies, such as previous versions of ASP.NET, Active Server Pages 2.0/3.0, or JavaServer Pages. If you understand the basics of Web programming, you should not have much trouble following along with this book's content. If you are brand new to ASP.NET, be sure to check out "Beginning ASP.NET 4: In C# and VB" by Imar Spaanjaars (Wiley Publishing, Inc., 2010) to help you understand the basics. In addition to working with Web technologies, we also assume that you understand basic programming constructs, such as variables, For Each loops, and object-oriented programming. You may also be wondering whether this book is for the Visual Basic developer or the C# developer. We are happy to say that it is for both! When the code differs substantially, this book provides examples in both VB and C#. This book explores the 4 release of ASP.NET. It covers each major new feature included in ASP.NET 4 in detail.