XHTML, the standard, was first released back in 2000. Roughly five years later we begin to see major websites revised to use this standard. Even the favorite whipping boy of standards-compliance punditry, Microsoft, presents their primary homepages, msn.com and microsoft.com in XHTML. Standards compliant XHTML sites are still the minority. The reason is simple. When the W3C released the new standard, the rest of the web running on HTML did not cease to function. Nor will the rest of the web, written in various flavors of HTML, cease to function any time soon. Without any pressing need to conform to the new standard, designers continue to use old, familiar methods. These methods will perform in any modern browser, so why bother switching?
These sentiments are similar to ones I experienced. A kind of "if it's not broke, don't fix it" mentality sets in. Whether HTML was "broken" or not is a different argument. To the casual Internet user, their standards are fairly direct. If a site displays without noticeable error and functions to their satisfaction, these standards are met. Whatever additional steps the browser took to make such display possible is irrelevant to most users. This kind of mentality is difficult to overcome in designers accustomed to their old methods.
Technical obstacles to adopting XHTML may be quite steep as well, especially as regards large, existing websites with complex scripting. Yet the time may eventually come where yesterday's "tried and true" HTML is little more than an ancient language, unable to be interpreted by modern electronic devices. Whether one agrees with the direction the W3C takes in the development of HTML is irrelevant, you are just along for the ride. With some perseverance, getting the hang of XHTML is possible. In form, it is not as different from HTML as Japanese is from English. Knowing HTML grants a basic knowledge of the language, it simply becomes a matter of learning a particular dialect. Even an original nay-sayer such as myself managed to do it.
Benefits of XHTML
There are 2 primary benefits to using XHTML. First is the strict nature of valid XHTML documents. "Valid" documents contain no errors. Documents with no errors can be parsed more easily by a browser. Though the time saved is, admittedly, negligible from the human user's point of view, there is a greater efficiency to the browser's performance. Most modern browsers will function well in what's usually referred to as "quirks" mode, where, in the absence of any on-page information about the kind of HTML they are reading, present a "best guess" rendering of a page. The quirks mode will also forgive many errors in the HTML. Modern browsers installed on your home computer have the luxury of size and power to deal with these errors. When browser technology makes the leap to other appliances it may not have the size and power to be so forgiving. This is where the strict, valid documents demanded by the XHTML standard become important.
The second benefit is in the code itself, which is cleaner and more compact than common, "table" based layout in HTML. Though XHTML retains table functionality, the standard makes clear tables are not to be used for page layout or anything other than displaying data in a tabular format. This is generally the primary obstacle most designers have with moving to XHTML. The manner in which many designers have come to rely on to layout and organize their pages is now taboo. Simple visual inspection of XHTML code reveals how light and efficient it is in comparison to a table based HTML layout. XTHML makes use of Cascading Style Sheets (CSS), which, when called externally, remove virtually all styling information from the XHTML document itself. This creates a document focused solely on content.
XHTML makes use of "div" tags to define content areas. How these "divisions" are displayed is controlled by CSS. This is known as CSS-P, or CSS Positioning. Trading in "table" tags for "divs" can be tough. Learning a new way of accomplishing an already familiar task is generally difficult. Like learning to use a different design program or image editor, frustration can be constant. Looking at "divs" as a kind of table cell might be helpful, though they are not entirely equivalent. As required by the XHTML standard, always make sure there is a DOCTYPE definition at the top of the document. This is not only required by the standard, but it will force Internet Explorer 6, currently the most common browser, to enter its "standards compliance" mode. IE6 and Firefox, both operating in standards compliance mode will display XHTML in much the same way. Not identical, but far better than IE6 operating in quirks mode. Learning how to iron out the final differences between displays is the final obstacle and can require a bit of tweaking in the CSS.
Clean code has multiple benefits. It creates a smaller page size which, over time, can save costs associated with transfer usage. Though the size difference may appear small, for someone running a highly trafficked site, even saving a few kilobytes of size can make a big difference. Further, some believe search engines may look more kindly on standards complaint pages. This is only a theory, though. In a general sense, any page modification that makes the content easier to reach and higher in the code is considered wise. Search engines, so it is believed, prefer to reach content quickly, and give greater weight to the first content they encounter. Using XHTML and "div" layout allows designers to accomplish this task more easily.
XHTML is the current standard set by the W3C. The W3C continues development of XHTML, and XHTML 2.0 will replace the current standard in the future. Learning and using XHTML today will help designers prepare for tomorrow. Valid XTHML produces no errors that might slow down a browser, and the code produced is clean and efficient. This saves in file size and helps designers better accomplish their search engine optimization goals. Learning XHTML is primarily about learning a new way to lay out pages. Though frustrating at first, the long term benefits far outweigh any initial inconvenience.