Quieres saber cuantos de tus paquetes de tu linux son “libre”

1.- instala vrms

aptitude install vrms

2.- ejecuta vrms

pandora:~# vrms
Non-free packages installed on pandora
figlet Frank, Ian & Glenn's Letters
unrar Unarchiver for .rar files (non-free version)
Reason: Modifications problematic
2 non-free packages, 0.4% of 472 installed packages.