Are all packages in MATE's PPA fully free?
Are all the packages in https://launchpad.net/~ubuntu-mate-dev/+archive/ubuntu/trusty-mate (and PPAs it points to as mandatory) fully free?
I am a member!
Don't have an definite answer to your question, but MATE is just GNOME2, basically, so I'd think the answer is probably yes. MATE is developed by Linux Mint though and they are not free software advocates. However my understanding is that Linux Mint does not develop any non-free software itself. It only includes third party non-free software.
I'm pretty sure that apart from Clem's non-leading involvement it's not a Mint project. Cinnamon is, though.
Anyway, I was referring to the caja-dropbox package in there. It's free, right (except that it depends on a non-free thing Trisquel won't go out and satisfy anyway)?