MATE (desktop environment)
MATE (/ˈmɑːteɪ/ MAH-tay) is a desktop environment composed of free and open-source software that runs on Linux, and other Unix-like operating systems such as BSD, and illumos.
Name
MATE is named after the South American plant yerba mate and tea made from the herb, mate. The name is stylized in all capital letters to follow the nomenclature of other Free Software desktop environments like KDE Plasma and LXDE. The recursive backronym "MATE Advanced Traditional Environment" was subsequently adopted by most of the MATE community, again in the spirit of Free Software like GNU ("GNU's Not Unix!"). The use of a new name, instead of GNOME, avoids naming conflicts with GNOME 3 components.
History
Perberos, an Argentine user of Arch Linux, started the MATE project to fork and continue GNOME 2 in response to the negative reception of GNOME 3, which had replaced its traditional taskbar (GNOME Panel) with GNOME Shell. MATE aims to maintain and continue the latest GNOME 2 code base, frameworks, and core applications.
MATE was initially announced for Debian on November 8, 2013, at its official website.
MATE became an official Arch Linux community package in January 2014.
Component applications

MATE has forked a number of applications which originated as GNOME Core Applications, and developers have written several other applications from scratch. The forked applications have new names, most of them from Spanish.


Development

MATE fully supports the GTK 3 application framework. The project is supported by Ubuntu MATE lead developer Martin Wimpress and by the Linux Mint development team:
New features have been added to Caja such as undo/redo and diff viewing for file replacements. MATE 1.6 removes some deprecated libraries, moving from mate-conf (a fork of GConf) to GSettings, and from mate-corba (a fork of GNOME's Bonobo) to D-Bus.
One of the aims of the MATE developers is to provide a traditional user experience while using the newest technologies. In MATE 1.20, which was released in February 2018, support for HiDPI was added and the GTK version got increased to 3.22. The MATE 1.22 release migrated many programs from Python 2 to Python 3 and from dbus-glib to GDBus. In an upcoming version, support for Wayland will be added.
Release history

Note that there are an odd number of versions between each official release. They are treated as versions under development, and are not announced as official releases.
Adoption
The MATE website lists 27 Linux distributions and 5 Unix-like operating systems that support the MATE desktop environment.
Reception
MATE was criticized for having no Wayland support but in version 1.28 Wayland support was "initially added". Some users are now sticking more to the Wayland support, as Wayland has significant improvements since.