Apache Subversion is a full-featured version control system originally designed to be a better CVS.
Headphones is a SABnzbd add-on that automates your music downloading. Import all your favorite artists from iTunes, and watch for any new albums be released.
A web-based interface for system administration. Using any modern web browser,advanced users can setup user accounts, Apache, DNS, file sharing and removes the need to manually edit Unix configuration files.
Usermin is a web-based interface for webmail, password changing, mail filters, fetchmail and much more.
Like the hand-held calculator, but it runs directly in your browser. A must have for any advanced math student.
RPM Fusion is a repository of add-on packages for Fedora maintained by a group of volunteers. RPM Fusion is not a standalone repository, but an extension of Fedora.