Comparison of XML and SGML
Robert Dornbusch
give recommendations for choosing SGML over XML, or vice versa? Are
there guidelines or rules of thumb for choosing one or the other based
on what you produce?
I'm currently using the "SGML Buyer's Guide" to determine what tools
would be best to move toward a single-source authoring environment.
However, the guide doesn't adequately detail whether to choose SGML or
XML specifically.
Any help would be appreciated,
Bob
Paul Batt
370E4BD4...@sdrc.com...
> I have a newbie question. Can anyone suggest any web pages or books that
> give recommendations for choosing SGML over XML, or vice versa?
You can't publish SGML documents on the web. XML you can. That's the most
obvious difference I'd say.
Paul
Christopher B. Browne
Sure, you can publish SGML documents on the web. There are lots of
them out there.
There are few "web browsers" that are able to cope with them, but the
same is largely true for XML, after all...
--
Those who do not understand Unix are condemned to reinvent it, poorly.
-- Henry Spencer <http://www.hex.net/~cbbrowne/lsf.html>
cbbr...@hex.net - "What have you contributed to free software today?..."
Lars Marius Garshol
* Robert Dornbusch
|
| I have a newbie question. Can anyone suggest any web pages or books
| that give recommendations for choosing SGML over XML, or vice versa?
| based on what you produce?
Given that XML software is so much more widespread and most SGML
software can work with XML, I'd say that if you don't need the extra
features of SGML you should go with XML.
This paper tries to say something about what XML can do that SGML
cannot, and also tries to explain some of the reasons for these
differences. The slides cover the same material, but in a slightly
different way.
<URL: http://www.stud.ifi.uio.no/~larsga/download/artikler/fin_sgml_98.html>
<URL: http://www.stud.ifi.uio.no/~larsga/download/artikler/fin_sgml_98.pdf>
--Lars M.
mot97piwa
>I have a newbie question. Can anyone suggest any web pages or books that
>give recommendations for choosing SGML over XML, or vice versa? Are
>there guidelines or rules of thumb for choosing one or the other based
>on what you produce?
The basic difference between SGML and XML is that the text describing the SGML
is 200 pages and the one for XML is less that 50 pages. XML sort the SGML
features that are realy useful to make the things simpler to boost the usage.
Martin Wickman
Yes, that is true, but there are somethings that are missing in XML
(afaik) that I would like to be able to handle. For instance, you
cannot specify datatypes in the DTD. Ie you cannot specify that a
value must be of type integer.
--
Design a system an idiot can use,
and only an idiot will want to use it.
Lars Marius Garshol
* mot97piwa
|
| The basic difference between SGML and XML is that the text describing
| the SGML is 200 pages and the one for XML is less that 50 pages. XML
| sort the SGML features that are realy useful to make the things
| simpler to boost the usage.
* Martin Wickman
|
| Yes, that is true, but there are somethings that are missing in XML
| (afaik) that I would like to be able to handle. For instance, you
| cannot specify datatypes in the DTD. Ie you cannot specify that a
| value must be of type integer.
This is a classic trade-off when designing systems and there are many
different approaches to it. Richard P. Gabriel has written a superb
analysis of this which is justly famous:
<URL: http://www.naggum.no/worse-is-better.html>
(unless you're interested in Lisp, skip to section 2.1)
SGML and XML more-or-less correspond to the-right-thing and
worse-is-better, respectively, although SGML is not quite designed in
the MIT/Stanford style described by Gabriel.
Most of his predictions have already seem to be coming true (pressures
for re-introduction of old SGML features, more integration, XML is
more widespread etc etc).
--Lars M.
Charles F. Goldfarb
>* Martin Wickman
>|
>| Yes, that is true, but there are somethings that are missing in XML
>| (afaik) that I would like to be able to handle. For instance, you
>| cannot specify datatypes in the DTD. Ie you cannot specify that a
>| value must be of type integer.
You can specify datatypes for data content by means of a notation attribute and
notation declarations. This works for both XML and SGML.
In Web SGML, you can also specify datatypes for attribute values.
--
Charles F. Goldfarb * Information Management Consulting * +1(408)867-5553
13075 Paramount Court * Saratoga CA 95070 * USA
International Standards Editor * ISO 8879 SGML * ISO/IEC 10744 HyTime
Prentice-Hall Series Editor * Definitive XML * Open Information Management
--