The SGML/XML Web Page
- Database containing over 2000 documents pertaining to SGML, XML, and related standards. Features a bibliography for SGML, vendors and service providers, software reviews, mailing lists, user groups, and projects.
Comparison of SGML and XML - A Note from the W3C detailing the differences and similarities between the two markup languages.
SGMLtools-Lite - Formerly Linuxdoc-SGML, SGMLtools offers a out-of-the-box SGML processing solution for technical (DocBook) documentation. [Open source, GPL]
SP - A free, object-oriented toolkit for SGML parsing, validating, and entity management.
Women Writers Project, ACM Crossroads Winter 1999 - This article from Crossroads Winter 1999 issue describes the use of SGML to encode literature archives for research, written by B. Fan. (December, 1999)