1. An Emacs major mode for editing SGML documents. PSGML is a major mode for editing SGML documents. It contains a simple SGML parser and can work with any DTD. (The most popular nowadays are the HTML DTDs. This package turns your emacs into the one of most powerful HTML editors and will be ultimately flexible as well, since you could upgrade your editor by just installing new DTDs). 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. Since psgml parses the DTD to allow you to edit SGML documents, you do need to have the DTDs installed in order to use psgml. Since psgml installs itself as an HTML mode in Emacs, it depends on sgml-data. Some other packages which also provide SGML DTDs are suggested, like debiandoc-sgml and linuxdoc-sgml. SGML, a language for encoding the structure of a document, is an ISO standard: ISO 8879:1986 "Information processing - Text and office systems - Standard Generalized Markup Language (SGML)". Psgml is a standard package for XEmacs, and thus this package does not install itself for XEmacsen. From Debian 3.0r0 APT

2. Emacs is an advanced and extensible editor. An Emacs major mode customizes Emacs for editing particular types of text documents. PSGML is a major mode for SGML (a markup language) documents. PSGML provides several functionalities for editing SGML documents: indentation according to element nesting depth and identification of structural errors (but it is not a validating SGML parser); menus and commands for inserting tags with only the contextually valid tags; editing attribute values in a separate window with information about types and defaults; structure based editing, including movement and killing; and also several commands for folding editing. From Redhat 8.0 RPM