Install ‘GNOME 2’ MATE Desktop in Ubuntu 14.10, 14.04

For Ubuntu users who prefer the classic Gnome 2 Desktop but not satisfied with Gnome Fallback session, MATE Desktop may be a good alternative.
The MATE Desktop Environment is the continuation of GNOME 2, which is under active development to add support for new technologies while preserving a traditional desktop experience.
MATE Desktop is available via the official repositories for various Linux distributions, including Arch Linux, Debian, Fedora, Gentoo, Linux Mint, openSUSE, Ubuntu 15.04. There’s also Ubuntu MATE, an official Ubuntu flavor, that uses MATE as the default desktop environment.

Install MATE in Ubuntu 14.04, 14.10:

MATE developers have create a few PPAs for current supported Ubuntu releases, including 14.04 Trusty and 14.10 Utopic.
For Ubuntu 14.04, open terminal from the Dash or by pressing Ctrl+Alt+T on keyboard. When it opens, run commands below one by one:

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 upgrade  sudo apt-get install --no-install-recommends ubuntu-mate-core ubuntu-mate-desktop

For Ubuntu 14.10, run below commands instead to add PPA and install MATE Desktop:

sudo add-apt-repository ppa:ubuntu-mate-dev/ppa  sudo add-apt-repository ppa:ubuntu-mate-dev/utopic-mate  sudo apt-get update  sudo apt-get upgrade  sudo apt-get install --no-install-recommends ubuntu-mate-core ubuntu-mate-desktop