XML: Catching the next Internet wave
Reviewed by Ross Owens
If the idea of Extensible Markup Language (XML) leaves you
cold, just wait a month or two. XML is destined to do for distributed
documentation what Java is doing for distributed applications. If you're
already excited about the promise of XML, congratulations. You're ahead
of a cresting wave.
Regardless of where you sit in relation to the coming XML
revolution, you'll benefit from Presenting XML by Richard Light,
(Sams.net, 1997) one of the very first books to focus exclusively on
this powerful markup language. Presenting XML provides a clear, sensible
look at XML, complete with necessary context for neophytes as well as
gory details for readers who are anxious to make the transition as soon
The opening section offers an indispensable overview. It traces the
roots of XML from SGML (Standard Generalized Markup Language), explains
the advantages of XML over HTML, and talks about the tools you'll need
to get up to speed.
Because context alone can't crystallize a concept (or run a
company, for that matter), the book's next two segments go into detail
and get down to business, explaining the key elements of an XML document
-- its tags, elements, attributes, Document Type Definitions (DTDs),
logical structure, and especially its physical structure -- a powerful
notion that could easily be characterized as a "paradigm shift" if that
weren't such a clich. These explanations might be slow going if you
don't have some prior experience with markup languages, but if you know
HTML, SGML, or both, you'll be fascinated to learn XML's similarities
and differences with its closest relatives.
Throughout all these explanations, Light goes out of his way to
make sure he hasn't lost you by including summaries at the beginning and
the end of each chapter. In addition, he provides helpful real-world
examples by taking you through the creation of a simple XML-based memo
application and by zeroing in on his area of expertise to explain the
development of an XML museum information application. Furthermore, Light
adds a great deal both to his credibility and to the language's by
regularly reminding you that Presenting XML was actually written in SGML
(of which XML is a subset) and by providing glimpses of the XML-like
tagging that was used in composing the very pages you are reading.
Light rounds out Presenting XML (with help from contributing
authors Simon North and Charles A. Allen) by looking to the future of
XML, taking inventory of already available XML software, examining the
efforts to complete the XML specification, and exploring potential uses
for the language. Although neither North nor Allen writes as engagingly
as Light, it's difficult not to get excited about the incredible
potential of this new language, even if you knew virtually nothing about
XML when you first picked up the book.
Without exception, XML is the most exciting and exhilarating
development in online documentation since HTML, and Presenting XML
provides an excellent introduction.
Ross Owens is the Executive Managing Editor of InfoWorld. He can be
reached at firstname.lastname@example.org.