You see, unlike the situation for some other DE's, Xfce users are happy, with Xfce.
On topic; as others have said, it's called Linux Mint MATE edition.
Why Michael only makes mention of Mint amongst a list of other distributions that MATE is easily installable on, i don't know. One could surmise that his general knowledge of Linux distros is lacking. Perhaps he doesn't realise Mint is still a distro that uses Ubuntu binary repos, or maybe thinks Mint only offers the Cinnamon environment and is unaware that the MATE edition features with equal prominence on Mint's download page.
(@Michael: i don't intend offence, merely pointing out how your lack of including this info could be perceived.)
There's already a solution for those who hate Unity as a desktop environment on their Ubuntu setup:
replace unity by mate