This format is used to create images without compression on Nikon Coolpix cameras. The created RAW files contain electronic data from the camera sensor. It is able to save more data compared with compressed photos. With NRW files you can set the exposure, white balance and other settings while preserving all the details in the image.
The SXW file format was originally created for StarOffice Writer, the word processing application for Sun Microsystem's StarOffice suite. Programs that can open SXW files include StarOffice Writer and OpenOffice.org Writer. To open an SXW file in Microsoft Word, it's usually possible by renaming it as a DOC file.