The software which comes with Nikon is View NX, I don't use it as I prefer Windows Live editing software. There is a very basic RAW feature with View NX but you can only do it on a very small photo, and it doesn't have many features.
NX-D is intended to replace the costly Capture NX2, and for free! Capture NX2 won't be upgraded after this replacement, I can't compare the two but if it's meant as a replacement it should be close to the original.
http://www.calphoto.co.uk/prod...
From dpreview:
Capture NX-D lacks the Control Point adjustments that were a feature of its predecessors (and were arguably the main original selling point)
http://www.dpreview.com/articl...
If that's the only difference then it should still be a good programme, I have downloaded it but haven't taken any RAW photos to try it on. I did try Nikon's Capture NX a few years ago as a free trial when I first got a DSLR, it looked very different but things change. My ability to understand it was limited too, there was no user manual with it but there is a downloadable manual to go with NX-D.
I have read that RAW programmes provided with some cameras are basic. If you buy a very expensive professional Nikon for example you would get Capture NX2 free, but couldn't expect to get it with a cheaper camera. I wonder what the future holds for those.