Agora is a Web-based, threaded discussion tool, similar to Usenet newsgroups. Agora remembers each user's preferences, and allows threaded, unread-only browsing. It offers the ability to manage several different groups, with different themes, forums, and administrators for each group. Agora offers a basic Web-based ICQ client, as well as a Web-based notes system.
aubng is a Usenet binary decoder implemented entirely in Perl5. It has a boatload of features, including: decoding of uuencoded and Base64 postings, assembling multi-part postings, remembering already seen binaries in a newsrc file, saving metadata about news postings, smart renaming of binaries with the same name, removal of duplicate binaries, and easy XML-based configuration. Aubng also features an extensible handler architecture, so it is easy to add your own features.
DBOX is a free communication package for ISPs. It supports a large number of message formats such as RFC/UUCP, ZConnect, Janus/Janus2, Alphabox, and GSbox. It is designed for large installations and includes a WWW package with an email/HTML gateway, an HTML online shop, support for POP3/IMAP4, and personal homepages with HTTP/FTP upload.
GBuffy will poll multiple mailboxes for new mail. It will list the number of new messages in each mailbox you configure. It will also highlight the mailboxes that have new mail, and you can display the message headers by pressing mouse button one on a mailbox. GBuffy is currently capable of watching MBOX, MMDF, Maildir and MH Folders. This version also supports IMAP4rev1 and NNTP with XOVER mailboxes, as well as displaying X-Face headers.
Gnus is an extremely powerful, configurable news and mail reader written in Emacs LISP for GNU Emacs and XEmacs. It provides threading, sorting, and article scoring; can retrieve messages via NNTP, local news or mail spool files, IMAP, POP, and other methods; and has features that make it efficient for reading news over low-speed network connections.
INN (InterNetNews) is an extremely flexible and configurable Usenet / netnews news server. It supports accepting articles via either NNTP connections or via UUCP, as well as serving out articles to reading clients via NNTP. It supports multiple different ways of sending outgoing articles to other hosts, as well as multiple different storage mechanisms for articles and article overview information via internal APIs. Compared to other news servers, INN is more complicated with a steeper learning curve, but is extremely flexible and configurable, comes with a large suite of supporting programs, and supports embedded filters in either Perl or Python.