they require software instruments developed by native instruments, which can be run inside ableton live -- but I'm still hoping this post is a joke.
Nope, sorry but I'm a noob
Basically as mholloway said, they're presets that are loaded by VST applications created by Native Instruments. You'll need to download/buy the NI VST application to be able to use them. Once the application is installed, you launch it using the normal VST method in Ableton (in the manual) and then depending on the NI VST application it should allow you to load the KSD file.
Some KSD files are intended for specific NI products but I believe (although I could be completely wrong) Kore can load most of them.
There is a free version of Kore (Kore player) that can be downloaded: http://co.native-instruments.com/index. ... replayerdl
Hope that helps