Ubuntu
Ubuntu packages are available (among other distribution) on OpenSuse Build System.
There's also repository mirror on Midgard website.
Add ubuntu repository to /etc/apt/sources.list:
deb http://download.opensuse.org/repositories/home:/midgardproject:/ragnaroek/xUbuntu_9.04/ ./
Check the version number of your Ubuntu and change URL accordingly
Update packages info and install.
apt-get update
apt-get install midgard
And then just proceed to set up your database and website.
