AllNews - Freeware newsreader for Windows 3.x/9x/NT that "should" also work in Win2K, XP, OS/2. Built to support simultaneous use of multiple servers.
Binary News Reaper - Also known as BNR, this is an open source, NZB capable news client for binary newsgroups only. Two detailed user guides are available on the website in PDF format. For GNU/Linux, Windows 95 and above.
Binbot - Commercial binary newsreader for Windows and GNU/Linux. A limited demo is available.
CancelMoose[tm] - Information about the NoCeM protocol in general, including a listing of news clients which understand NoCeM, a protocol for reducing spam and other undesired Usenet articles.
Diiva - A newsreader designed for browsing encoded pictures in newsgroups. It allows you to see previews of images before they're downloaded. Available for Mac and Windows.
Good Net-Keeping Seal of Approval - Certain minimal standards for writing and evaluating Usenet software that conforms to netiquette. Ratings of newsreaders and of a few web-based ways to gain access to newsgroups.
Hellanzb - Open Source application able to retrieve nzb files and fully process them. Mac OS X and FreeBSD versions are supported, and there is also an unsupported Windows version.
JBinUp - Presents this Java based, freeware client for uploading binary files; includes a support forum.
Mozilla Mail/News - Technical information and project documentation of the integrated email and news client in the Mozilla Suite.
NewsCoaster - Open source offline and online newsreader for the Amiga.
NewsGreed - Open source Java application which automatically downloads binary articles from newsgroups. Supports automatic re-assembly of files split among articles.
NewsReaders.com - Explanation of Usenet and list of newsreaders and other Usenet-related software. Directory of newsreader software sorted by operating system with brief descriptions and links to official download sites.
NNTPGrab - Free and open source news grabber for binary newsgroups. Versions for Windows, Mac OS X and GNU/Linux are available.
NZBGet - Command-line based binary newsgrabber for NZB files, written in C++. Supports client/server mode and automatic par check and repair.
Nzbperl - Open source, NZB based, command-line Usenet downloader written in Perl. Runs under several flavors of Unix including Mac OS X and also under Windows via Cygwin.
Pan - Open source newsreader designed for both text and binary newsgroups. It supports offline reading, scoring, killfiles, and multiserver access. For Unix-like operating systems and Windows.
SABnzbdPlus - Open source, NZB capable binary newsgrabber written in Python, server-oriented using a web-interface. The active successor of the abandoned SABnzbd project.
SLRN - Threaded, text based, open source newsreader for Unix, VMS, OS/2, and Win32 systems. Highly customizable. Allows to redefine keys and to write custom macros. Full support for scoring articles, complex filters and killfiles.
XPN - Open source newsreader for Windows and GNU/Linux. Supports scoring, off line reading and X-Face headers.