SGML: DSSSL Status (April 1996)

Subject: Re: DSSSL Lite mailing list [was: SGML in medical informatics?]

Date: Fri, 19 Apr 1996 05:26:31 GMT

From: bosak@netcom.com (Jon Bosak)



[Steve Pepper:]

> The DSSSL-lite mailing list still exists but has been *extremely*
> quiet recently. It was originally set up to provide a forum for
> discussions about defining a subset of DSSSL that could serve as a
> style sheet standard for on-line documents.
> 
> It largely fulfilled that task during the course of 1995 and provided
> much valuable input to the editors of the DSSSL standard. However, now
> is the time for action rather than talk -- it is up to the vendors to
> provide us with implementations and signs are that that will happen
> during 1996.

Steve deserves our heartfelt thanks for his work in setting up and
maintaining the DSSSL-lite list.  It has proven essential to the
effort to define a semantic specification language for the Web that
goes beyond the proprietary concerns of the currently dominant Web
browser vendors.

> [...]
> I would suggest that further discussions about DSSSL and DSSSL Online (or
> whatever we ended up calling it) take place here in comp.text.sgml.

I agree that comp.text.sgml is a good place for future discussions of
DSSSL and dsssl-o.

The following blurb was written for a workshop on dsssl-o that will be
held on May 15 during the upcoming SGML Europe conference in Munich.
It may prove useful to some readers as a summary of where we stand at
the moment.

Jon

========================================================================

DSSSL (Document Style Semantics and Specification Language) is an
International Standard, ISO/IEC 10179:1996, for specifying document
transformation and formatting in a platform- and vendor-neutral
manner. DSSSL can be used with any document format for which a
property set can be defined according to the Property Set Definition
Requirements of ISO/IEC 10744. In particular, it can be used to
specify the presentation of documents marked up according to ISO 8879,
Standard Generalized Markup Language (SGML).

DSSSL consists of two main components: a transformation language and a
style language. The transformation language is used to specify
structural transformations on SGML source files. For example, a
telephone directory structured as a series of entries ordered by last
name could, by applying a transformation spec, be rendered as a series
of entries sorted by first name instead. The transformation language
can also be used to specify the merging of two or more documents, the
generation of indexes and tables of contents, and other
operations. While the transformation language is a powerful tool for
gaining the maximum use from document bases, the focus in early
versions of DSSSL will be on the style language component.

Within the style language, it is possible to identify a number of
capabilities that for one reason or another should be considered
optional for early implementations. Recognizing this, the designers of
DSSSL designated certain features of the style language as optional
and created a Core Query Language and a Core Expression Language
specifically in order to make more limited implementations
possible. However, they did not define any particular subset of the
style language component within the standard itself, but rather left
that task to industry organizations and standards bodies. The DSSSL
Online (dsssl-o) Application Profile is intended to be the first such
specification.

Dsssl-o is designed particularly for the style specification
requirements of online SGML browsers and editors.  In addition to the
core features required by the DSSSL standard, it adds DSSSL options
needed to support vertical scrolling and basic print output.

The current DSSSL Online Application Profile is the result of several
months of discussion leading up to a pivotal meeting of SGML tools
vendors in Boston on December 9, 1995.  Under the guidance of the late
Yuri Rubinsky, the participants reviewed and approved a comprehensive
list of DSSSL flow object classes and specified the minimally
supported values for the characteristics associated with each class.
The resulting document can be seen at the following address:

   http://occam.sjf.novell.com:8080/docs/dsssl-o/do951212.htm

While the current document specifies most of what is needed for the
implementation of dsssl-o applications, further work remains to be
done in order to specify the dsssl-o subset of DSSSL functions.

---
Jon Bosak, SunSoft   2550 Garcia Ave., MPK17-101, Mountain View, CA 94043
A Davenport Group Sponsor        http://www.ora.com/davenport/README.html