What is Alien?

Due to the different linux distributions (and their derivates), there are several different installation methods, and their corresponding file formats. Alien is a program that converts between these file formats: rpm (Red Hat), dpkg (Debian), stampede slp (Stampede Linux, and Slackware tgz. If yo uhave the need to install a package from another distribution then the one you are currently using, you can use Alien to convert and install the package on your system.

Although Alien has a large version number, the software is still rather experimental, and has many bugs and limitations. Chances are quite big that this will not change, even though it has been used many times by many people for many years.

Therefor an important warning: Alien should not be used to replace important system packages, like sysvinit, shared libraries, or other things that are essential for the functioning of your system. Many of these packages are set up differently by Debian and Red Hat, and packages from the different distributions cannot be used interchangably.
The rule of thumb here is: if you can’t uninstall the package without breaking your system, don’t try to replace it with an Alien version.

How to use Alien?

First of all you need to install Alien itself. You can do this by adding the Ubuntu Universe repository to your list of sources and then using the command:
$sudo apt-get install alien
in a terminal or console.

Then you can install the .rpm (or other) using:
$sudo alien -k name-of-rpm-file.rpm
Where: For more info I can refer you to the alien manpage (man alien) on how to install other kinds of packages and all the options available.