Re: [xml-dev] Wikipedia on XML

[Elliotte Rusty Harold <elharo@ibiblio.org>]

On Fri, Aug 7, 2009 at 2:17 PM, Michael Kay<mike@saxonica.com> wrote:

> That dodges the question "What kind of thing is XML" by saying "It's the
> same kind of thing as SGML". That's not a very good answer to the question.

We would of course include a link to the SGML entry here. Hmm, maybe
we should steal from that entry? The SGML entry says:

The Standard Generalized Markup Language (ISO 8879:1986 SGML) is an
ISO Standard metalanguage in which one can define markup languages for
documents. SGML is a descendant of IBM's Generalized Markup Language
(GML), developed in the 1960s by Charles Goldfarb, Edward Mosher and
Raymond Lorie (whose surname initials were used by Goldfarb to make up
the term GML[1]).

SGML provides an abstract syntax that can be implemented in many
different concrete syntaxes. For instance, although it is the norm to
use angle brackets as tag delimiters in an SGML document (per the
reference concrete syntax defined in the standard), it is possible to
use other characters instead, provided that a suitable concrete syntax
is defined in the document's SGML declaration.[2] For example, an SGML
interpreter could be programmed to parse GML markup. In GML, tags are
bounded by a colon on the left and a full stop on the right; an :e
prefix denotes an end tag: :xmp.Hello, world:exmp..

so our first sentence could be:

"XML (Extensible markup Language) is a W3C recommended metalanguage in
which one can define markup languages for documents." or, better yet,
"XML is a W3C recommended syntax in which one can define markup
languages for documents." I actually think that's the most accurate
description yet. I'm happy with the notion that XML *is* a *syntax*. I
don't think it's really a language, and I'm not sure what a
metalanguage is either.

-- 
Elliotte Rusty Harold
elharo@ibiblio.org