RefDB is a reference database and bibliography tool for SGML, XML, and LaTeX documents. Command-line tools allow interactive or scriptable access to the data which are stored in a SQL database. RefDB can also be accessed through a Web interface, a SRU interface, or via editor extensions (Emacs/vim). Libraries for Perl and PHP are available for programmers. RefDB provides sophisticated character encoding handling, using Unicode by default.
sgml2x is a script designed to help applying a DSSSL stylesheet to an SGML or XML document. It has a couple of interesting features, such as multiple possible stylesheets per document class, easy integration of new stylesheets by adding a simple new definition file in a configuration directory (system-wide, per-user, or per-project), and automatic selection of a default stylesheet to be used. It is already set up for DocBook SGML/XML.