Icecast is a streaming media (audio/video) server which currently supports Ogg (Vorbis and Theora), Opus, WebM and MP3 streams.
It can be used to create an Internet radio station or a privately running jukebox and many things in between.
Darkice is a simple command-line streamer that takes audio input from jack or alsa input and streams it in Ogg Vorbis to icecast server.
Both are easy to install on Debian via apt (icecast2 & darkice)