CAPTURE NX-D
It’s made for Nikons, and it’s completely free to download
Capture NX-D is available as a free download from the Nikon website at It’s up to date with support for the latest Nikon D-SLRs, and as new models are introduced, Capture NX-D should be the first software to support them. Another key advantage is that it exactly replicates the Picture Controls, white balance and other settings of your Nikon.