PSGML is a major mode for editing SGML and XML documents.  It works
with GNU Emacs 19.34, 20.3 and later or with XEmacs 19.9 and later.
PSGML contains a simple SGML parser and can work with any DTD.
Functions provided includes menus and commands for inserting tags with
only the contextually valid tags, identification of structural errors,
editing of attribute values in a separate window with information about
types and defaults, and structure based editing.

To use psgml, put the following setup into your ~/.emacs:

	(require 'psgml-startup)

Ports of PSGML are initially created by shige <shige@FreeBSD.org> and
kuriyama@FreeBSD.ORG.

WWW: http://www.lysator.liu.se/~lenst/about_psgml/
WWW: https://sourceforge.net/projects/psgml/