X is XHTML
Those fine people at the World Wide Web Consortium (WC3) are never
satisfied, and, of course, they only have our best interests as wayfarers
in the web whenever they propose changes to the web's languages.
XHTML (eXtensible Hypertext Markup Language) is one of those changes.
In the view of WC3 HTML allows authors to get away with sloppy markup-ing.
What's more browsers are very forgiving, and rather than crash your
badly written page they display what they can. Sounds pretty bad, doesn't
it!?
So XTML is much more strict. It will improve your markup writing,
and you'll feel a lot better for it.
The main differences with HTML are
1. tags are case sensitive and must be in lower case;
2. all tags must have an end tag (e.g. </p>) and be properly nested;
3. all attribute names must be in lower case and values in quotes.
XHTML is stricter for a good reason. It transforms HTML into a subset
of XML, the Big Daddy of markup languages. (XML means eXetensible Markup
Language.)
This will allow a much more diverse exchange of information between
all sorts of equipment. Today mobile phone, pc, web, email. Tomorrow
your toaster, walking pole, bicycle, fishing rod... anything.
The kind people at WC3 have provided an open source tool that turns
your sloppy HTML into well written XHTML.
Click here and good luck!