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.
oXygen is an XML editor that supports any XML document, and works with XML Schemas, DTDs, Relax NG schemas, and NRL Schemas. It has powerful transformation support that allows you to edit XSLT and XSL-FO documents and to obtain documents in the desired output format (such as HTML, PS, or PDF) with just one click. It also includes a complete Subversion client, support for flattening XML Schemata, an XML Schema instance generator, integration with the X-Hive/DB, MarkLogic and TigerLogic XML databases, editing actions on the diagram, and a rename refactoring action.
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.