HTML Comes of Age: XHTML - Two Great Tastes that Taste Great Together (Page 2 of 7 )
HTML is a stogy octogenarian that helped fuel the massive assimilation of the Web into our daily lives but which is now holding the Web back from what it can truly become. It is inflexible, extended only through the messy process of Microsoft or Netscape (well, AOL now) adding a new tag then battling for market approval. It makes creative Web design difficult. Pages that bounce between script and HTML code in a single page make for a mind-numbing dance that is hard to maintain and debug.
In stark contrast, XML has little or nothing to do with formatting. It is all about meta data, data about data, which identifies what data is. So if I put the string 'Horatio' in HTML, you have no idea what that string is, except maybe through some complex context algorithm. But if I wrap that string in a pair of XML tags <FirstName> and </FirstName>, it becomes trivial to pluck that string out of the page and know exactly what to do with it. XML lets me define my own tags, create custom attributes that further describe the data, and makes it easy to move data across platforms that otherwise wouldn't have the time of day for each other.
The World Wide Web Consortium (W3C), the standards body that decides these things, has put XML and HTML together, taking the best of each and putting it into XHTML. Two great tastes that taste great together. The future of the Web will be founded on an extensible formatting markup language that is flexible, lets you create your own tags, and will make it far easier to design and develop true Web applications.
The promise of XHTML is that it will make Web sites more adaptable while supporting existing sites, as long as those existing sites are HTML 4.01-compliant.
XML is not the HTML-killer it was touted in its early days, but XHTML will most certainly kill off HTML. And it's about time.