Ubuntu MATE Remix Alpha1
Most things. The .iso image should boot (from DVD or USB), the Live session should work, the installer should work and the installed system should also work. Notice the heavy use of "should", YMMV. The is an alpha project, running on an alpha distribution that was put together by a novice Debian and Ubuntu contributor.
Ubuntu MATE 14.10 Alpha1
The very first alpha of Ubuntu MATE 14.10.