We've sprinkled a number of tips, tricks, and hacks throughout this book, along with style guidelines, examples, and instructions. So why have a special chapter on tips, tricks, and hacks? Because it's where many readers will turn when they pick up this book for the first time. HTML and XHTML are the languages, albeit constrained, that make the Web the exciting place that it is. And interested readers want to know, "How do I do the cool stuff ?"