Speaking of aptitude, it does remove automatically installed package if no other package depends on it, or recommends it. This behavior can be changed by configuration entries in /etc/apt/apt.conf, /etc/apt/apt.conf.d/*, etc.
To show any installed packages that aren't "auto" and which are dependencies or recommendations of other packages, in short, packages that aren't marked "auto" but could (should?) be, order aptitude search '~i!~M(~R~i|~Rrecommends:~i)' Go through this list and, as root, mark the ones you don't need with aptitude markauto PACKAGE When done, aptitude search '~g' shows what can be purged from the system. Regards, jvp.
