The KlassModeler is a tool for visually creating and documenting classes. It is not unlike other UML design tools except for four major differences: it focuses only on the class-diagramming aspects of UML and leaves out the use cases, actors, and other things, it generates code, it reads existing C++ header files, and it can create HTML documentation.
Ccdoc is a Javadoc-inspired tool that automatically generates HTML Web documentation from C++ programs by parsing the source file headers. It was designed to aid the collaboration between package users and package developers. It runs on FreeBSD, Linux, Mac OS X, Solaris, and Windows (98, 2k, Me, and XP).
XML to DDL is a set of Python programs that converts an XML representation of a database into a set of SQL or DDL (Data Definition Language) commands. In addition, it can examine the difference between two XML files and output a sequence of SQL statements (normally ALTER statements) to bring one database up-to-date with the XML schema. You can also download the XML schema directly from the database. Finally, there's a tool to convert your schema into HTML for documentation purposes. XML to DDL currently supports the most recent versions of PostgreSQL, MySQL, Oracle, and Firebird databases.