Instructions for Installing RPM Files Using Alien

Installing Alien

You can install alien itself from the Ubuntu Universe repository by adding the repository to your list of sources and doing:

$sudo apt-get update
$sudo apt-get install alien


Installing the .rpm file

To install the .rpm file, you first need to convert it to a .deb file which can be installed on Ubuntu.
I assume that you downloaded the package to your Desktop (~/Desktop is the directory)
You can convert the .rpm to a .deb by using the following commands.
$cd ~/Desktop
-This will change the directory to your desktop, where you have the .rpm file.

$sudo alien -k name-of-rpm-file.rpm
- This will convert the .rpm to a .deb.
- The “-k” will keep the version number. Otherwise alien adds a “1″ to the version number.
- Tip: Use Smart Tab Completion to avoid mistyping the file names

$sudo dpkg -i name-of-deb-file.deb
- This will install the .deb package

Try reading the alien manpage for more details on how to convert other kinds of packages and the options available.

source:

http://ubuntu.wordpress.com/2005/09/23/installing-using-an-rpm-file/