n00bs on Ubuntu posted a guide about installing Mixxx DJ Software on Ubuntu 11.04

Mixxx is free, open source DJ software that gives you everything you need to perform live mixes. You can install Mixxx 1.9.0 by adding the mixxx ppa and install it using a terminal command. When Mixxx is started for the first time you will be asked for the location where you store your music files.

  Install Mixxx DJ Software On Ubuntu 11.04