nzbdump is a free tool that displays the contents of an NZB file. Nzbdump is not a newsreader or downloader, and cannot download files for you. It`s main a diagnostic tool that you might be able to use if you`re having trouble with an NZB file. NZB files are files that are used to index newsgroup articles. They can be used by many newsreaders to help piece together complicated multi-part newsgroup binaries.