The fifth edition of this book represents a significant change in structure and content to address HTML5. The book is similar to the previous edition in maybe a third of the content; otherwise, it is an all-new effort. Most obviously, as compared to the previous editions, which focused mainly on XHTML and HTML 4, this edition focuses on HTML5, which represents both a return to the markup past and the unveiling of an exciting future of Web applications. However, we do retain some information from previous editions because in order for this work to be truly complete, we must not focus only on the future but also present all the elements supported in browsers today, including the archaic, proprietary, and standard (X)HTML tags. These will still be encountered for years to come, and we want this book to provide the reference you need in addressing their syntax. CSS coverage has been expanded greatly to fully cover CSS 2.1 as well as every proprietary and emerging CSS 3 property supported in one or more popular shipping browsers circa 2009. No value judgment is made; if Internet Explorer has supported a proprietary CSS feature for the last decade, it’s included. However, we do avoid presenting CSS features that are truly speculative in great depth, but where appropriate, we summarize or present pointers to the emerging syntax.
The ramification of the increased markup and CSS coverage is simply the book doesn’t have space left to do everything it did before. Teaching nearly everything about HTML and CSS in prose form and then presenting a complete syntax reference for the technologies would have produced a book well over 2,000 pages. We were well on the way to that when we adjusted our efforts to create what you have in your hands, a solid reference book that may be used for years to come. This isn’t to say that learning material is not present at all. There are very solid introductory chapters for the markup and CSS sections, which should succinctly address details and standards issues. There just isn’t step-by-step cookbook for each element or property. Given the maturity of the Web industry, we aimed not for the complete tutorial, but instead for the complete reference.
It should go without saying that more markup changes to HTML and CSS are inevitable. HTML5, in particular, is a complete moving target, and rather than punting on it, we took the best shot at its first release version as it settled in late 2009. Because of the inevitable changes given HTML5’s rapid evolution, the support Web site, http://htmlref.com, should be considered an important bookmark for readers looking for updates or the unavoidable correction.
