refdb-mode is a minor mode for Emacs that implements an interface to RefDB, a reference management and bibliography tool for SGML, XML, LaTeX, and Muse documents. It integrates nicely with psgml, nxml-mode, AucTeX, and muse-mode. refdb-mode provides the complete functionality of the RefDB command line clients from a graphical interface. You can add and edit references, notes, and styles, run queries, and insert the results as citations into your DocBook, TEI, LaTeX, or Muse documents. You can also look up cited references in the database right from your document. You can create, transform, and view these documents with a mouse click. This amounts to an integrated authoring environment for markup languages with reference management and bibliography support.
SPIN_py is a Python module that wraps the SP SGML parser. It does not follow SAX, nor DSSL, but it performs a similar task. It has code to build (and pretty-print) trees from C++ or from Python, and it has an interesting object model, with virtual C++ objects, based on PyObject_HEAD.
uni2ascii and ascii2uni provide conversion in both directions between UTF-8 Unicode and more than thirty 7-bit ASCII equivalents, including RFC 2396 URI format and RFC 2045 Quoted Printable format, the representations used in HTML, SGML, XML, OOXML, the Unicode standard, Rich Text Format, POSIX portable charmaps, POSIX locale specifications, and Apache log files. It can also convert between the escapes used for Unicode in languages such as Ada, C, Common Lisp, Java, Pascal, Perl, Postscript, Python, Scheme, and Tcl.
Quoter is a simple tool (filter) that takes HTML, XML, or SGML files as input and sends them back out as output with their quotation marks fixed. It handles Microsoft's non-standard quotes, typical Unix conventions (`` and ''), and straight single and double quotes. It knows to leave untouched anything in comments, scripts, or tags.
BHL is an Emacs mode which enables you to convert plain text files into HTML, LaTeX, Texinfo, SGML (Linuxdoc), and TXT files. The BHL mode handles three levels of sections, many sectioning styles, common font-styles, any kind of lists, tables, URLs, horizontal rules, and Wiki names. BHL handles a list of links (lol) and a table of contents (toc): you can browse the lol and the toc, insert them where you want, and update the sections' numbers with one keystroke.
doclifter helps with lifting documents with nroff markup to XML-DocBook. Lifting documents from presentation level to semantic level is hard, and a really good job requires human polishing. This tool aims to do everything that can be mechanized, and to preserve any troff-level information that might have structural implications in XML comments. TBL tables are translated into DocBook table markup, PIC into SVG, and EQN into MathML (relying on pic2svg and GNU eqn for the last two).