I shouldn't seem that way to anyone reasonable.
I know what TeX is. I should know what luatex is because I've been to their website, read through some links and even read through the introduction to their manual, and still I don't know.
And just listen to yourself: if I want to know what luatex is I shouldn't find out on their own website, I should have to go to Wikipedia?!
Do you know what it is? You've managed to reply to me twice and in neither of those replies have you simply stated: "luatex is software that does x. You'd want to use to to do y."