However, because it is an XML application, you need to play by the
rigid rules of XML markup. What makes XHTML documents different from
HTML 4 documents is that you need to be absolutely sure that your
code is well-formed (i.e., exactly follows the syntax rules), you
must declare the DTD that the document uses, and you must use the
xmlns attribute to indicate the XML namespace.
These issues are discussed in the following sections.
31.2.1. Tools
Because
XHTML
is still an emerging standard, as of this writing, none of the
popular commercial web authoring tools generate XHTML standard
documents automatically. This situation should change as XHTML is
ushered in as the definitive standard, replacing HTML 4.01. In the
meantime, Windows and UNIX users can use the W3C's browser and
editing tool, Amaya, to generate XHTML documents (see http://www.w3.org/Amaya/ for more
information).
Any tool that is programmed not to rewrite code it doesn't
recognize (Macromedia Dreamweaver, Adobe GoLive 4 and higher, and
Microsoft FrontPage 2000) should leave your XHTML-formatted tagging
alone. There is an extension to Dreamweaver (available for download
at http://www.macromedia.com/exchange/dreamweaver/;
search for XHTML) that will generate the proper document type and
namespace declarations.
Another option is to convert existing HTML documents into XHTML. You
could use the command-line utility called Tidy, created by David
Raggett of the W3C. Tidy cleans up many aspects of an HTML file,
including converting it to well-formed XHTML. It is available at
http://www.w3.org/People/Raggett/tidy/.
Microsoft FrontPage 2002 can also convert selected HTML into
well-formed XHTML by clicking on "Apply XML Formatting
Rules." Microsoft notes, however, that while selected HTML code
is converted, it does not convert the HTML page to a complete XML or
XHTML document.