SGML Open

This group of SGML developers came together in 1993. It is an industry consortium that wants to promote the interoperability of SGML applications and more widespread use of SGML.

SGML Open has a great Web site, shown in figure 30.5. Visit both the HTML version and the SGML version (via Panorama) of its home page.

Fig. 30.5  The SGML Open home page (at http://www.sgmlopen.org) is one you should visit.

SGML Open is in the business of developing and selling SGML products. If you want to know what’s happening in the world of SGML products and applications, SGML Open can offer plenty of information.

EWS

The European Workgroup on SGML (EWS) is a collection of European publishers, printers, and typesetters. It’s responsible for a set of DTDs known as the Majour DTD. The DTDs are based on the AAP standard and cover scientific papers and journals. They are available through SGML browsers. For more information, see the following URL:

gopher://trick.ntp.springer.de/11/sgml

Collaboration on SGML Standards

You can keep up on the ongoing standards development projects on the Web. One of the best sources of information is the SGML Web Page at http://www.sil.org/sgml/sgml.html (see fig. 30.6). Robin Cover has done a marvelous job of organizing links to vital Web pages that you can use. You can spend months running down links on your favorite subjects.

Fig. 30.6  The SGML Web Page helps you locate the information that you need on current SGML projects.

You will find FAQs, tutorials, bibliographies, conference announcements, news, software reviews, information on current projects, and great miscellaneous links. The projects include:

•  SGML Projects and applications—General projects and applications, academic projects and applications, and government and industry applications

•  Special topics on SGML (ISO 8879)

•  Standards related to SGML—document style semantics and specification language, standard page description language, open document architecture, and other standards

There is more here than you can imagine. The projects are important to keep an eye on.

HyTime

There is much to say about HyTime, short for Hypermedia/Time-based Structuring Language. The applicable standard is ISO 10744. As with most projects, HyTime deals with standards.

Do some reading on HyTime. Start with its Web pages at http://techno.com/TechnoTeacher/HyTime.html, and chase down the links. This link should remain stable. When in doubt, go back to Robin Cover’s page at http://www.sil.org/sgml/sgml.html.

The official standard of HyTime is not in the public domain. A copy of it costs $98.

HyTime is an extension of SGML. It defines how SGML structures can be used to deal with individual document objects for use in hypermedia. HyTime engines, which are implementations of HyTime, enable development companies to build applications. Licenses are expensive, however.

Read Making Hypermedia Work: A User’s Guide to HyTime, by Steve DeRose and David Durand. It costs approximately $70 and is worth it. You can obtain information on ordering a copy from http://cs-pub.bu.edu/students/grads/dgd/order.html.

HyTime is one of the most important SGML projects today. It is another egg whose time to hatch has nearly come. It will attract much public attention in the next few years, so keep an eye on it.

SMDL

Standard Music Description Language (SMDL) is one of the HyTime applications. The applicable ISO standard is ISO 10743:1995. The architecture of applications built according to this standard supports music either alone or together with text and graphics. It handles the time sequencing information necessary for sound applications, so that you are not hung up by a network server wait signal in the middle of a waltz. The language can help build applications for business, publishing, or recreation.

ICADD

Not everyone who uses SGML has perfect sight. For those with visual disabilities, the International Committee on Accessible Document Design (ICADD) is a lifesaver. An ICADD DTD supports document definitions for Braille, large print, and voice synthesis. The applicable ISO standard is ISO 12083 ANNEX A.8. There’s also an HTML-to-ICADD transformation service that translates HTML documents into Braille documents. Check the URL at:

http://www.ucla.edu/ICADD/html2icadd-form.html

UTF

News agencies have chosen SGML as their method for sending news around the globe. The DTD is still in development. Universal Text Format (UTF) will replace the current standards of the International Press Telecommunications Council and the Newspaper Association of America, IPTC 7901 and ANPA 1312.

Fred at OCLC

Fred at the Online Computer Library Center (OCLC) is not a standard, but it is an exciting project. It has real potential. It’s still a private application, but portions of it are available on the World Wide Web. A list of related links can be found at the following URL:

http://www.sil.org/sgml/gen-apps.html#oclc

Suppose, for example, that you receive SGML tagged text without an associated DTD. That’s a problem. Fred is designed to create a DTD from the document automatically by extracting its tags and building a grammar structure from the document instance.