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 source code and issue database for the old Perl version of Natural Docs, version 1.52. It is still available but no longer being updated. Please see NaturalDocs.org for the 2.x source code and issue...