Especially inexperienced Linux users sometimes face a rather difficult situation. They have for example a program in a Red Hat RPM package but need a Debian DEB package. When the original developer of the program does not exist, or does not provide their program for different Linux distribution it can quickly lead to a dead end. Luckily, there is a converter that can help you convert some Linux distribution packages between each other - alien.
alien is an experimental software that is able to convert various Linux distribution package (Red Hat RPM, Debian DEB, Stampede SLP, Slackware TGZ, and Solaris PKG) between each other. Although many users use this program for years, it is still far from complete and has many bugs and limitations. It is, however your best bet if you want to convert some non-system critical Linux packages.
Install alien program
First thing you need to do is to install the alien program. You can do it easily via the terminal.
sudo apt-get install alien
Then, if you launch alien you will see the following command options.
alien launched in Ubuntu terminal
How to convert DEB to RPM
You can use alien to convert DEB package to RPM, in order to do so use the following example for your needs.
sudo alien -r yourpackage.deb
This will create a RPM package from your DEB file.
How to convert RPM to DEB
Same way you can use alien to convert RPM package to DEB.
sudo alien -d yourpackage.rpm
The opposite conversion that will create DEB package from your RPM file.
How to convert other Linux distribution packages
Much like in previous examples, alien can be used for other conversion types. Except for the previously mention DEB and RPM packages, it can also convert Stampede SLP, Slackware TGZ, or Solaris PKG packages.
Still having trouble converting Linux package
This article just covers the basics of alien program usage. Should you need more specific information, please check the alien developer website or Ubuntu help sites where you can find them. Also, you should generally avoid trying to convert system-critical files as they might end corrupted after the conversion.