At first glance, you might assume that HTML5 is the fifth version of the HTML web-page-writing language. But the real story is a whole lot messier.

HTML5 is a rebel. It was dreamt up by a loose group of freethinkers who weren’t in charge of the official HTML standard. It allows page-writing practices that were banned a decade ago. It spends thousands of words painstakingly telling browser makers how to deal with markup mistakes, rather than rejecting them outright. It finally makes video playback possible without a browser plug-in like Flash. And it introduces an avalanche of JavaScript-fueled features that can give web pages some of the rich, interactive capabilities of desktop software.

Understanding HTML5 is no small feat. The most significant challenge is that people use the word HTML5 to refer to a dozen or more separate standards. (As you’ll learn, this problem is the result of HTML5’s evolution. It began as a single standard and was later broken into more manageable pieces.) In fact, HTML5 has come to mean “HTML5 and all its related standards” and, even more broadly, “the next generation of web-page-writing technologies.” That’s the version of HTML5 that you’ll explore in this book: everything from the HTML5 core language to a few new features are lumped in with HTML5 even though they were never a part of the standard.

This brings you to the second challenge of HTML5: browser support. Different browsers support different parts of HTML5, and there are some painfully new features that still don’t work in any browser, anywhere.

HTML5 is more than a markup language—it's a dozen independent web standards all rolled into one. Until now, all it's been missing is a manual. With this thorough, jargon-free guide, you'll learn how to build web apps that include video tools, dynamic drawings, geolocation, offline web apps, drag-and-drop, and many other features. HTML5 is the future of the Web, and with this book you'll reach it quickly.

The important stuff you need to know:

• Structure web pages in a new way. Learn how HTML5 helps make web design tools and search engines work smarter.
• Add audio and video without plugins. Build playback pages that work in every browser.
• Draw with Canvas. Create shapes, pictures, text, and animation—and make them interactive.
• Go a long way with style. Use CSS3 and HTML5 to jazz up your pages and adapt them for mobile devices.
• Build web apps with rich desktop features. Let users work with your app offline, and process user-selected files in the browser.
• Create location-aware apps. Write geolocation applications directly in the browser.