ykhov, welcome to LinuxQuestions!
I wouldn't say Knoppix is a "configured version of Debian". Remember, Debian is supposed to be the all-purpose operating system, so what *you* want to do with Debian might be totally different from what someone running a cluster of rendering machines wants to do. Of course, you are right in the sense that Knoppix is configured pretty well for a desktop user, but I just wanted to highlight the fact that Debian isn't tailored to be your average desktop. It installs what everyone is likely to need, then you'll have to take it from there by yourself, or using the tools available.