Diablo - - Open source newsfeeding and newsreading software. Runs on most flavours of Unix.
DNews - - Usenet NNTP news server for most flavours of Unix, as well as Win9x/NT. Handles full newsfeeds while conserving system resources. Can use Suck feed option. Anti-spam features. Academic licensing also available.
Ftp.tin.org: Server Software Repository - Hosts several Usenet server packages including Leafnode, C news, Diablo and INN, and also very old applications like A news and B news for historical purposes.
Hamster Classic - - Light, open source NNTP and e-mail server. For Windows 95 and above, also runs under GNU/Linux with Wine.
Hamster Playground - - Free newsserver and mailserver software for single computers and small family or company networks. Developed from the same source as Hamster Classic. Source available. [Windows.
Hamster with news.individual.net - - Short tutorial with screenshots on the configuration and use of Hamster with individual.net news server. May also be helpful for other servers.
Highwinds Software - - Offering several products for discussion software: Cyclone News Router, Typhoon News Server and Twister Discussion Server. All products run on a Unix/Linux/Solaris type of operating system.
How to Become a Usenet Site - Periodic posting about the basic steps involved in configuring a machine to store USENET news.
INN: The InterNetNews Package - - Complete open source Usenet system. De facto standard for handling news routing, news spool and serving the spool to customers. Available for various versions of Unix from the Internet Software Consortium. How-To's and mailing lists.
Leafnode - - Easy to use, open source, IPv6-capable NNTP news proxy for Unix/Linux systems, designed for small networks.
Mib Software NewsrA+e - - A subscription service to measure how well your newsserver is receiving articles. Benchmark against other servers to determine whether you are receiving and delivering "full feed" Usenet content in the groups you carry.
MPNews - - Modular Windows software. Supports full news feeds, web and RSS interfaces and automatic filtering. 30-day trial version available.
NewsCache - - Usenet News cache server for Unix. Distributed under the GNU Public license. Reduces required network bandwidth of the news server. Multiplexes between different news servers and allows offline news reading.
NewsPlex - - Personal server utility which allows any news-reader to access several news-servers simultaneously, by merging their content into one single news-server. Freeware for GNU/Linux, Solaris and Windows.
Newsstar - - A multithreaded NNTP transport designed to transfer Usenet articles as quickly as possible between a local server and multiple remote servers, with score-based killfiles. Open source software, supports INN, s-news and sn.
NNTPCache - - A cache server for Unix platforms. Free to use for individuals, non-military, non-profit research groups, non-profit organizations and medical or educational government departments. Others are required to license the software.
NNTPRelay - The only carrier-class news router for Windows NT. Freely available and redistributable. Also available from the same authors is the freely available news server program "Tortoise" for Windows NT.
Papercut - - Open source news server written in Python. Its main objective is to integrate existing web based message board software, like Phorum which is supported, with a Usenet front-end.
sn - - A small news system for sites with a slow connection to the Internet that serve, perhaps, a few dozen newsgroups. Also includes a mail-to-news filter. For Unix-type systems.
SuckMT - - Uses client NNTP to download news messages in order to feed them into your local server. Free download, FAQ, sample scripts, planned features. [Linux, Windows NT, source/binary.
Tortoise - Freely available news spool server for Windows NT, based on the NNTPRelay program from the same authors.
Wikipedia: News Server - - Presentation of news servers and explanation of differences between transit, reader and hybrid (also called "sucking" or cache) servers.