Raw2Nef 3.34 for Mac was available as a free download on our application library. The actual developer of this free software for Mac is Miguel Bañón. The application lies within Design & Photo Tools, more precisely Converters.
From the developer:
Raw2Nef allows you to convert files from new cameras types into a sort of Nikon Electronic Format (NEF) raw file that can be edited by Nikon Capture NX 2, version 2.4.6. As of today, Raw2Nef supports the following cameras: Sony A6000, Sony A7, Sony A7II, Sony A7R, Nikon D750, and Nikon D810.
You may want to check out more software for Mac, such as AFELO, MePub or ContentaMRWConverter, which might be similar to Raw2Nef.