Not sure what you mean, But phpld can be used for any type of directory you want. By default install it has no categories so you can add what categories you want and any custom fields you require quite easily in versions 4.1 and the I think soon to be released 4.2.
I am talking about the script of Directory of Directories like listofdirectories[dot]com or directorycritic[dot]com
PHPLD can be used to make something very simular. Also why not add your directories to our lists at http://www.mitredesign.co.uk/directory-lists.html
We've done some custom work for people where you can quickly submit to different directories and track your progress, but out of the box phpLD is mostly a directory, so that means you could indeed list other directories, and many have used phpLD this way.