Hi,

Here we use phpDoc to document our code. Like Village Idiot's way of handling doc it uses comments in code, and it is very similar to Java's docblock syntax

/**
* This describe function usage
*
* @param int $id Parameter description
* @return mixed Return desc
*/

The same bloc repeats for classes, modules (altough this doesn't realy exists in PHP) , files, etc.

The main advantage is it has a parser that can build documentation in HTML format straight from your code !

Mor information on http://www.phpdoc.org/