Directory

No. Directories link out, not in. And if you make your directory a reciprocal link directory you almost certainly will end up being considered a link farm or in a bad neighborhood.

Do you think that the DaniWeb directory is a link farm? :(

You're not a link farm if you have a directory. But sites with little to no reputation (a.k.a trust) with Google that exchanges links with a site that is considered to be a part of a link farm run the risk of being considered part of that link farm. Naturally that's a great reason to be banned from Google. So if the site is new and/or very small running a reciprocal link directory can potentially be harmful to their rankings.

Some links directoryscripts, can make a link exchange with "tier site"

Ex: You run dirforlinks.com for the directory links but your link's partners make a backlink to yourwebsite.com.

I have no problem w/search engines .

But for a "good" link, The only relevant directory is Dmoz.
1 link in dmoz equal hundred's "bad" links
or a quality link provided by a specialized directory
Like "daniweb.com/directory" is certainly recognized by search engines
for an it directory specialist.

Directories are not all that bad, it depend on how you design it. If you can make it a standard directory all the best.