What is the difference between the security tag on http://serverfault.com/? http://serverfault.com/questions/tagged/security

Why not just post these questions on stack overflow, under the 'security' tag?

Stack Overflow is about programming in general, this website specializes in security on its own. Furthermore, this site accepts security questions that may not necessarily be programming related

StackOverflow trashes any question that isn't explicitly related to programming. If your question is, "How can I securely implement a password storage scheme with PostgreSQL and Erlang?", then StackOverflow is right for you. If your question is, "How can I break this guy's securely-implemented password storage scheme, written in PostgreSQL and Erlang?", then you would probably want something like this.

Because any question on SO about using or configuring software is downvoted, complained about and sent to superuser.

That's a nice SO clone, What is it built upon? Obviously it isn't a SO site.

StackExchange is the whitelabel SO clone service Joel and Jeff are hoping to grow with VC funds.

Close, StackExchange is the whitelabel SO-derivative hosted by Fog Creek. But it is not what they are hoping to grow with VC funds, it's a separate entity than Stack Overflow proper, which is what they're trying to grow with VC funds. It's a little non intuitive but not terribly so.

"Rooted" is a common colloquialism here in Australia :-)

Basically if your box gets rooted, you're fucked ;)

it almost means the same thing in this context as well :-)