Can Debian identify rarely used packages?

Solution 1:

As already mentioned, popularity-contest should help. It will display the oldest unused packages at the bottom. Uninstall those, but with a watchful eye on whether or not there's stuff depending on them installed.

Here's a snippet of the output:

1294222606 1292570417 vlc /usr/lib/vlc/plugins/gui/libqt4_plugin.so
1294222606 1292570109 xulrunner-1.9.2 /usr/share/xulrunner-1.9.2/chrome/classic.jar
1294222606 1292507839 ttf-dejavu-extra /usr/share/fonts/truetype/ttf-dejavu/DejaVuSans-Oblique.ttf
1294222606 1292507459 x11-utils /usr/bin/xprop

The colums mean atime, ctime, package-name, and file accessed.

One other tool for removing stuff you don't need is deborphan. Running mine gives me:

libaio1
libpython3.1

It means there are no packages depending on those two libraries, implying that I can safely remove them. Newer version of apt-get should make this usage of deborphan less needed, but such orphaned libraries pop up from time to time.

Have a look at this post as well.

Solution 2:

The popularity-contest package is able to collect this information but I do not know if you can directly access it.