The DE stands for Desktop Environment.

Running KDE on your n800 is basically like running windows xp on it. KDE does everything windows xp can do and more.

Linux has many layers, and KDE is just the stuff at the very top. Windows on the other hand is all squished together, and you can't separate any of the parts out. KDE does not need any drivers or anything like that, all that is handled by the software that comes with the tablet.

This is one of the great advantages of open source. In theory, you could just take the top layers of windows and put them on the n800, but MS wont let you. The only way you can get XP on here is if you install the whole thing, which is also impossible since there aren't any drivers for it. The KDE developers had never even tested KDE on a tablet like this when they were developing it, but since everything in opensource is interchangeable it works perfectly.