Natural Docs is an open-source documentation generator for multiple programming languages. You document your code in a natural syntax that reads like plain English. Natural Docs then scans your code and builds high-quality HTML documentation from it.
SourceForge houses the sourcecode and issue database for the old Perl version of Natural Docs, version 1.52.
SYMPLiK RANGEHOOD is a Javadoc-like tool for Oracle database. This pure-Java program "sucks up" data dictionary and object sourcecode from database and generate document for Tables, Views, Triggers, Packages, Procedures, Functions, and others.