Congratulations! Good luck with Trisquel. I believe you can install mate from the Ubuntu PPA for Trusty. If you're using Trisquel 7 (which I assume you are) the commands are as follows:
$ sudo add-apt-repository ppa:ubuntu-mate-dev/ppa $ sudo add-apt-repository ppa:ubuntu-mate-dev/trusty-mate $ sudo apt-get update $ sudo apt-get install mate-desktop-environment Good luck! More info here: https://trisquel.info/en/wiki/installing-mate
