"The first XSLT essential is its Extensible Markup
Language (XML) base (also see the ``Glossary of XSLT Terms''
Sidebar). XML is the universal data format designed to encode
everything: algorithmic data, programs and documents from purchase
orders to biblical translations, in any human language, on any kind
of computer and operating system. XML looks like HTML except it's a
bit more complicated. In fact, one of XML's design goals is to
generalize HTML in a way that preserves the comfort of HTML adepts.
There's even a flavor of XML called XHTML that permits direct
interpretation as HTML. Linux Journal frequently publishes articles
on different aspects of XML.
A fully XML-ized world is a simpler one, in many ways. To
analyze the operation of an accounts payable department, for
example, you don't need to know who reports to whom, who is due for
a three-week vacation and all those other messy human details. If
you can draw a diagram that shows invoices coming in and payments
going out, perhaps with authorization records spawned along the
way, then you have abstracted what ought to be the essential
This is an intoxicating insight. It promises that a system that
can transform one XML document (invoice) into one or more other XML
documents (payment check, authorization records) and at least
organizes, and possibly solves, all meaningful organization
automations. That's why XSLT seems so important now."