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.
RTV is an application that allows you to view and interact with reddit from your terminal. It is compatible with most terminal emulators on Linux and OSX.
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.