Ubuntu, Remove crap

$ sudo apt-get purge libreoffice-*
$ sudo apt-get purge firefox*
$ sudo apt-get purge thunderbird*






List all installed packages (pipe to grep to search for a specific pattern):
$ dpkg --get-selections | grep <pattern>

remove all libreoffice packages:

$ sudo apt-get purge libreoffice-*

remove orphaned packages, i.e. installed packages that used to be installed as an dependency, but aren't any longer. Use this after removing a package which had installed dependencies you're no longer interested in:
$ sudo apt-get autoremove

see what packages are available to install matching a  pattern
$ apt-cache search <pattern>

To see all the files installed by a package like python-kivy-examples:
$ dpkg-query -L  <package name>