Ubuntu for Internet radio

apt-get install icecast2

Afterwards we must edit /etc/icecast2/icecast.xml. Most default values should work fine for now, but you should change the passwords in the ... section. The source-password is the password that Ices2 will later on use to connect to Icecast2; the admin-password is the password that the admin will use in Icecast2's web interface; we won't use the relay-password, but anyway you should change it.

vi /etc/icecast2/icecast.xml

[...]
    <authentication>
        <!-- Sources log in with username 'source' -->
        <source-password>password1</source-password>
        <!-- Relays log in username 'relay' -->
        <relay-password>password2</relay-password>

        <!-- Admin logs in with the username given below -->
        <admin-user>admin</admin-user>
        <admin-password>password3</admin-password>
    </authentication>
[...]

Afterwards edit /etc/default/icecast2 and set ENABLE to true:

vi /etc/default/icecast2

# Defaults for icecast2 initscript
# sourced by /etc/init.d/icecast2
# installed at /etc/default/icecast2 by the maintainer scripts

#
# This is a POSIX shell fragment
#

# Full path to the server configuration file
CONFIGFILE="/etc/icecast2/icecast.xml"

# Name or ID of the user and group the daemon should run under
USERID=icecast2
GROUPID=icecast

# Edit /etc/icecast2/icecast.xml and change at least the passwords.
# Change this to true when done to enable the init.d script
ENABLE=true

That's it already, we can now start the Icecast2 server: /etc/init.d/icecast2 start

You can now direct your browser to http://:8000/ (replace 192.168.0.100 with your own IP address or FQDN) and browse through the web interface.

There is a couple more settings to change depending on your intended use. But that should get you started.