DownloadDaemon is a comfortable download-manager with many features like one-click-hoster support, etc.
It can be remote-controled in several ways (web/gui/console clients), which makes it perfect for file- and root-servers, as well as for local use.
RadioBox is open-source broadcasting solution that relays on client-server architecture. It consists of media server that runs as a service and listens for socket connections of graphical interfaces (web access, Windows GUI, Linux GUI, etc...)