Yes, Mate is one of them. https://trisquel.info/en/wiki/installing-matetells you to: sudo add-apt-repository ppa:ubuntu-mate-dev/ppa and sudo add-apt-repository ppa:ubuntu-mate-dev/trusty-mate
But the procedure is very similar when installing XFCE4.12 instead of 4.10, which is in the Trisquel repositories.
I just don't like the idea of adding repositories from different non-free distributions to my sources.list file.
