What program is DMOZ.org built on?

[Raval]

I'd like to know what is the name of the program DMOZ.org is built on.

I am interested in building a web directory.

[Darkhack]

Unfortunely it is closed source. http://en.wikipedia.org/wiki/Dmoz#Software
Here are some alternatives though...

http://www.astanda.com/adp/
http://www.particlesoft.net/particlelinks/
http://yald.eotz.com/
http://kamads.com/kamads_ads/linkleaverDL.php
http://www.freedirectoryscript.com/
http://www.c97.net/product.php?p=dirpro