[MUD-Dev] Re: Modular MUD

[Bruce]

From: Adam J. Thornton <adam at phoenix.Princeton.EDU>
Date: Monday, August 31, 1998 1:27 PM

>
> [ .... some crypto stuff elided ... ]
>
>If I'm developing a protocol that doesn't really need much in the way of
>links, would I be better off writing an SGML DTD rather than an XML DTD?


The linking part of XML is the XLink working draft
(<URL:http://www.w3.org/TR/1998/WD-xlink-19980303>)

XML's big advantage other than all of the PR is that it is a much simpler
version of SGML.

>From the XML FAQ (<URL:http://www.ucc.ie/xml/>):

A.5   Aren=91t XML, SGML, and HTML all the same thing?

=A7 Not quite. SGML is the `mother tongue', used for describing thousands=
 of
different document types in
many fields of human activity, from transcriptions of ancient Sumerian
tablets to the technical
documentation for stealth bombers, and from patients=91 clinical records =
to
musical notation.

HTML is just one of these document types, the one most frequently used in
the Web. It defines a single,
fixed type of document with markup that lets you describe a common class =
of
simple office-style report,
with headings, paragraphs, lists, illustrations, etc, and some provision =
for
hypertext and multimedia.

XML is an abbreviated version of SGML, to make it easier for you to defin=
e
your own document types,
and to make it easier for programmers to write programs to handle them. I=
t
omits the more complex and
less-used parts of SGML in return for the benefits of being easier to wri=
te
applications, easier to
understand, and more suited to delivery and interoperability over the Web.
But it is still SGML, and
XML files may still be parsed and validated the same as any other SGML fi=
le
(see the question on XML
software).

Programmers may find it useful to think of XML as being SGML-- rather tha=
n
HTML++.
--------------------
and:


A.8   How does XML make SGML simpler and still let you define your own
document types?

To make SGML simpler, XML redefines some of SGML=91s internal values and
parameters, and removes
a large number of the more complex and sometimes less-used features which
made it harder to write
processing programs (see Appendix A of the XML specification).

But it retains all of SGML=91s structural abilities which let you define =
your
own document type. It also
introduces a new class of document which does not require you to use a
predefined document type. See
the questions about `valid' and `well-formed' documents, and how to defin=
e
your own document types in
the Developers=91 Section.

--------------------

I'd argue that using XML is a bit of a better answer than SGML since it i=
s
easier to parse and has more backing right now in the document circles.

 - Bruce