NZBScout - NZBScout is a modern indexer for verified NZB files posted to Usenet network.
NZBGet.com - Fast, reliable, and feature-packed NZB downloader.
nZEDb - nZEDb is a newsgroups indexer.
NZBGet - The most efficient usenet downloader.
FindNZB - FindNZB is a search engine for Usenet newsgroups with a possibility to download .nzb files.
SABnzbd - SABnzbd is a free/open-source cross-platform binary newsreader written in Python.