As you may know, Ubuntu MATE 16.04 Alpha 1 has been recently released in all the flavors except Unity. Among the Ubuntu spins that have received a lot of changes and enhancements is Ubuntu MATE, which is the newest member of the Ubuntu family.
Martin Wimpress, the main developer of MATE and Ubuntu MATE has announced that all the MATE-related changes that were implemented on Ubuntu 16.04 Alpha 1 are available via the MATE PPA for Ubuntu MATE 15.10 as well.
To get these changes on Ubuntu MATE 15.10 Wily Werewolf, you have to add the PPA to your system, update the local repository index and perform a regular system upgrade:
$ sudo apt-add-repository ppa:ubuntu-mate-dev/wily-mate
$ sudo apt-get update
$ sudo apt-get dist-upgrade
Optional, to revert the changes, do:
$ sudo apt-get install ppa-purge
$ sudo ppa-purge ppa:ubuntu-mate-dev/wily-mate