Mezzo is the default desktop of SymphonyOS
Ranked in these QuestionsQuestion Ranking
Pro Available as .deb package
Mezzo is available as a .deb package, which makes it very easy to install it on Debian or Debian derivatives such as Ubuntu.
Con Possibly discounted
There's not much new information about Mezzo around, all the articles or forum posts about it are quite old which may be an indication that it's probably abandoned now.