NWD - Navisworks Document is a file extension that you can download online when you really need to the most. It can basically be created using Navisworks. This is a handy program that can be used for simulation of different designs regarding architecture. You will also be able to use this program for reviewing these designs as well. This program and extension is handy for viewing camera viewpoints, animations, and much more. These are the type of files that also contain source data files so you will be able to view different documents alone. You will also be able to view different NWD files with Navisworks Freedom. If you want to publish your files, you will be given that option as well. It is very easy to use.