D Programming/Documentation comments

The -D option to the dmd activates the generation of Ddoc. This means, special comments in the code are used to write a HTML file. The advantage of code-comments are:
 * code and documentation are near at each other. Better chance to be consistent
 * easy to use

dmd generates documentation per module.

CandyDoc
Enhancement to DDoc, to have an navigation. It can be found on the helix website.