From LQWiki

Alien is a program that converts between the rpm (Red Hat, .rpm), dpkg (debian, .deb), stampede (slp), and Slackware (tgz) file formats. If you want to use a package from another distribution than the one you have installed on your system, you can use alien to convert it to your preferred package format and install it.

External links

Alien package converter (www.kitenet.net)