SGML
ISO 8879:1986, Information Processing
-- Text and Office Systems -- Standard
Generalized Markup Language (SGML)
This is an ISO standardised derivative
of an earlier IBM "GML". It allows
the structure of a document to be
defined, and the logical relationship
of its parts. This structure can
be checked for validity against a
" Document Type Definition ", or
DTD. The SGML standard defines the
syntax for the document, and the
syntax and semantics of the DTD.
See books -- Eric van Herwijnen's
"Practical SGML" and Charles Goldfarb's
"SGML Handbook". Some of the points
generally broght up in (frequent)
discussions of SGML follow.
- See also:
- Klensin on SGML
High level markup
An SGML document is marked up in
a way which says nothing about the
representation of the document on
paper or a screen. A presentation
program must marge the document with
style information in order to produce
a printed copy. This is invaluable
when it comes to interchange of documents
between different systems, providing
different views of a document, extracting
information about it, and for machine
processing in general. However,
some authors feel that the act of
communication includes the entire
design of the document, and if this
is done correctly the formatting
is an essential part of authoring.
They resist any attempts to change
the representation used for their
documents.
Syntax
The SGML syntax is sufficient for
its needs, but few would say that
it is particularly beautiful. The
language shows its origins in systems
where text was the principle content
and markup was the exception, so
a document which contains a lot of
SGML is clumsy. There is always,
of course, an element of personal
taste to syntax.
There are few obvious comments one
could make.
Tools
For many years, SGML was generated
by hand, by people editing the source.
This has lead to a hatred of SGML
among those who prefer their own
mark-up language which may have been
quicker, more powerful, or more familiar.
The advent of WYSIWYG editors and
solid SGML applications should improve
that facet of SGML.
Archive
There are a number of SGML archive
sites. In Germany, there the Darmstadt
archive .
See also: HyTime , HTML , Hypertext
Document formats . Davenport. group
.
A public domain parser, SGMLS, exists.
There is an archive of SGML related
information at ifi.uio.no
Tim BL