Sometimes you find packages on your Ubuntu box and you don't know how they got
there. This happens often with automatically installed programs. To find the packages that
require (or recommend) another package, you can use the
aptitude why command.
Below you see (an edited) example session where I needed to find the program that used a package.
$ aptitude search timidity i A timidity - Software sound renderer... i A timidity-daemon - runs TiMidity++ as a sy...
In this example I first search for the package that I didn't know and wanted to
remove. You can see from the uppercase
A that this package is installed
automatically. First I need to know if the program is system critical. So I use
why command to find the packages that use this package.
$ aptitude why timidity i prboom Recommends timidity
prboom package isn't automatically installed. It's a game that I haven't
played for a few years, so I remove it.
$ aptitude remove prboom
And we're done.