Kim Lester (kim@dfusion.com.au)
Wed, 12 Jan 2000 18:12:18 +0000
Existing Doc Systems, Part 3 (XML)
==================================
Warning: This is mostly guesswork.
Most comments that apply to SGML apply to XML.
I admit to not knowing the exact difference between the two
but I believe it to be roughly the following:
SGML is an ISO standard (ominous/arguable benefit :-))
XML is a W3 Consortium standard
XML (Extensive Markup Language)
---
http://www.w3.org/XML/
http://www.w3.org/XML/1999/XML-in-10-points [good intro]
http://www.oasis-open.org/cover/sgml-xml.html
XML is the new universal format for web based information.
XML is essentially the same as SGML (perhaps technically a subset)
but it defines a few issues more rigidly which makes the XML
based formats easier to parse in software.
XML vs HTML
-----------
The difference between XML and HTML is that HTML tags define
how text/data is displayed. XML tags define what the text/data
is (eg author/title etc). How these are displayed is a separate
issue.
XML and DocBook
---------------
DocBook is an SGML DTD.
XML doesn't necessarilty require a DTD but it is a good idea (??)
There will be an XML - DocBook DTD.
An alpha version can be found at:
http://www.nwalsh.com/docbook/xml/
XML Editors/Viewers and other Software
--------------------------------------
It is anticipated that XML browsers will become available
"soon".
Look at the w3.org site. There is a range of XML software.
XSL (XML Style Sheet)
---
XSL is to XML what DSSSL is to SGML (phew!)
(ie it defines how XML looks on screen/paper)
http://www.w3.org/TR/xsl
RDF (Resource Description Framework)
---
http://www.w3.org/RDF/Overview.html
RDF is deigned to hamdle the following web based activites
andsits on top of XML:
sitemaps
content ratings
stream channel definitions
search engine data collection (web crawling)
digital library collections
distributed authoring
XPointer - refer http://www.w3.org/TR/NOTE-xptr-req
XLink - refer http://www.w3.org/TR/NOTE-xlink-req
There are lots of other acronyms (DOM, XDL XSLT etc) which
I am not going to mention as they are going off the point.
Most pros and cons are same as for SGML with the following
additions.
Pros
----
Benefits of SGML but simpler
Appears to be the nex big techno "wave"
DocBook DTD (almost) available for XML
Cons
----
Aspects of related standards not complete (Pointers,Links)
Few/no current browsers support XML
Less tools than SGML
This archive was generated by hypermail 2.0b3 on Wed Jan 12 2000 - 13:14:53 EST