Demokritos is a server implementation of the Atom Publishing Protocol. It also provides a library that can be used for the development of other Atom-related applications.
Gnews Alert is GTK+/GNOME based. It will go out to news sources periodically and parse out breaking news alerts, then display a popup that shows you the news semi-as-it-happens!
Kticker is a news ticker widget that downloads news headlines from selected sites and displays them on the screen periodically.
mail2news-easy is a utility to convert mail to news and news to mail.
mail2nntp is a bridge from email realm to the newsgroup one. It can be used to replicate a mailing-list on a newsgroup server. It is a generic toot, using NNTP network commands.
Newts is a modern, actively-maintained implementation of notesfiles, a concept which is half Usenet and half bulletin board.
nntpfs is a FUSE module for mounting the data offered by NNTP servers. Read-only access to the servers is provided. The Filesystem in Userspace (FUSE) interface allows user application code to create its own filesystems and publish them using kernel support.
Straw is a desktop news aggregator for the GNOME environment. Its aim is to be a faster, easier and more accessible way to read news and weblogs than the traditional web browser.
uRSSus is a cross-platform RSS/Atom aggregator, similar in scope and functionality to Akregator, Straw, and others.