There is this PPA (that I do not use):
https://launchpad.net/~tsvetko.tsvetkov/+archive/ubuntu/cinnamon
The usual warning applies: this software being out of the control of
Trisquel, it may include proprietary software or even malware. Even if it
does not now, it could tomorrow along an apparently trifling update.
If you decide to trust who is behind the PPA:
$ sudo add-apt-repository ppa:tsvetko.tsvetkov/cinnamon
$ sudo apt-get update
$ sudo apt-get install cinnamon
Or you can add the PPA through the "Other Software" tab of "Software &
Updates" in the "System settings" (and install it with the "Synaptic package
manager").
