We all know that from last one year web directories has lost their importance in search engine optimization industry and it is considered as bad links by Google. It has happened because the spammer from all our the world made lot of spam directories and start selling links from just 0.l25 cents. Even the SEO consultants are also started considering it as low cost link building methods.
Web directories are build by many software and scripts like Gossamer-Threads, Phpld, esyndicate etc. We just make a survey of the low qualities links send by Google from time to time to various website which are under manual penalty and found that Google always refered one or more web directories which are made of Phpld script.
I think phpld is most popularity web directory script and its free version is mostly used by the directory spammers.
With the time all such directories will be closed. More than 10000 are already dead