Here is the official link from Oracle on how to install oracle-xe on Ubuntu.
I just tried it on my Virtual Box machine with Ubuntu 10.4 .
But since I am not familiar with Linux.. And I am sort of forced to use it if i still want to work on my Mac and on oracle-xe..
I made a mistake on swap file size... I left it default.. Everythin ok until i tried to install oracle-xe. It was complaining that the swap file was too small for the installation..
Here is the link on how to increase the swap file on ubuntu:
It is the official site of ubuntu..
I would like to share it with everyone cause it troubled me for sometime.