SGML and the Web 
From the World Wide Web Consortium, this page provides a collection of links to SGML resources. Learning and using SGML, specifications and reports, groups and discussion forums, and tools and software are the major categories here.
The SGML/XML Web Page 
Excellent collection of reference information and software pertaining to SGML and XML. Features news items, event information, special topics, introductions, and related standards.
An introduction to SGML
This document summarizes key facts on SGML for the technically inclined reader. Organized by a table of contents, the reader may start at the beginning, or chose a section of interest.
Generic SGML over the Web
Contains information on the World Wide Web Consortium's activities in the area of SGML and XML. Offers links to overviews, drafts and related publications.
SGML FAQs
Collection of several FAQs covering SGML.
SGML grammar builder project
Contains details on Fred, an ongoing research project at OCLC Online Computer Library Center, Inc. that studies the manipulation of tagged text.
Standards Related to SGML
Links to standards information for DSSSL , HyTime, XML and SPDL.
Yahoo!'s SGML page
Yahoo!'s directory for Standard Generalized Markup Language (SGML).