Along with the official Ubuntu flavors, Ubuntu MATE 15.04 Vivid Vervet alpha 2 was released yesterday. Read on to find out what's new.

Ubuntu MATE is an unofficial (that will probably change in the future) MATE-based Ubuntu flavor. For those not familiar with MATE, this is a GNOME 2 fork introduced after GNOME 3 and GNOME Shell replaced the classic desktop metaphor. Currently, MATE only supports GTK2, but the plan is to add GTK3 support with MATE 1.12.

Compared to Ubuntu Mate 14.10, the latest Vivid alpha 2 (there was no alpha 1) release introduces some new packages installed by default: (there was no alpha 1)

MATE Tweak (a MintDesktop fork) - lets you configure which icons to show on the desktop, enable/disable compositing, change the window buttons layout, show/hide icons in menus and buttons and more;

MATE Menu (a MintMenu fork) - a searchable menu for the MATE panel. This is not the default menu, but you can add it to the panel by right clicking the panel, selecting Add to Panel and then adding "MATE Menu";

Totem has been replaced by VLC.

MATE Menu (installed but not used by default)

If you're using Ubuntu MATE 14.04 LTS, the changes mentioned above won't sound new to you. That's because Ubuntu MATE 14.04 was released after 14.10 (back when Ubuntu 14.04 was released, Ubuntu MATE didn't exist) and it already incorporates these changes.

There is one new MATE Tweak feature though: you can now use it to switch between Compiz and Marco, just like in Linux Mint 17.1 MATE, an option that wasn't present in Ubuntu MATE 14.04:

new default theme: Yuyo-Dark (developed by Furthermore, Ubuntu MATE 15.04 ships with a(developed by Sam Hewitt ) and there's also a light "Yuyo" alternative that's installed by default:

Yuyo Dark theme

Yuyo theme

The new Yuyo themes still need some work - for now, some UI elements such as check boxes and radio buttons aren't rendered correctly, that's why Ambiant-MATE is still used for the live session and the LightDM theme, mentions the Ubuntu MATE 15.04 alpha 2 - for now, some UI elements such as check boxes and radio buttons aren't rendered correctly, that's why Ambiant-MATE is still used for the live session and the LightDM theme, mentions the Ubuntu MATE 15.04 alpha 2 release announcement

updated the Ambiant-MATE and Radiant-MATE icon themes with green icons;

added a few new community contributed wallpapers;

enabled X zapping via Ctrl+Alt+Backspace;

enabled screen reader activation via LightDM indicators and LightDM key bindings;

enabled touch to click by default for touchpads;

enable Tilda pull-down terminal integration. Press F12 to show/hide;

all MATE package updates from Debian have been automatically synced to Ubuntu 15.04 and are available in Ubuntu MATE 15.04 alpha 2;

ubuntu 15.04 has adopted multilib GObject introspection runtime (gir) which means Caja plugins now work "out of the box";

other bug-fixes.

Download Ubuntu MATE 15.04 Vivid Vervet alpha 2

via Ubuntu MATE blog

The link above includes the official release notes so make sure you read them before testing the latest Ubuntu MATE 15.04 alpha 2!