The cinnamon web page https://launchpad.net/~gwendal-lebihan-dev/+archive/cinnamon-stable?field.series_filter=quantal asks the user to: add-apt-repository ppa:gwendal-lebihan-dev/cinnamon-stable Which I did.So I thought that's all I need in order to proceed and issue apt-get -y install cinnamon Well, it could not find it, and the web page does not elucidate any further.