Alien is a package to convert between RPM, DEB or TGZ packages.
- alien [-d|-r|-t]] file.[deb|rpm|tar.gz]]
"Alien does the rest, by either generating the standard debian packaging that works most of the time, or, if there is a patch file in /usr/share/alien/patches that matches the file, applying the patch, which creates a customized debian/ directory and debian/rules, and then using that to build the package."