Debian/Unneeded packages

From Linux Hints

Old and not longer required packages and configuration files tend to accumulate over time as dependencies change. Try these commands (install deborphan package first).

Remove left configuration files

 dpkg --purge $(deborphan --find-config)

You can run this several times until you get an error.

Remove orphaned libraries

dpkg --purge $(deborphan | grep -v 686)

(Otherwise you'll remove libc-i686). Be careful with this, if you've installed some libraries for development, but don't have explicit dependencies. Again, you'll want to run this several times.

Remove other stuff

If you want to get carried away, look at the output of:

deborphan --guess-all

Also try the -n (turn off nice) flag.