Mir compositor with Wayland apps support. It's goal is to be intuitive understandable. It was developed by Canonical, discontinued, now developed by Ubports. Originally it looked like Mac OS. Mobile interface was added for ubuntu phone. To add support for Android apps libhybris was created and added to Unity8.
Ranked in these QuestionsQuestion Ranking
Pro Consistent GUIs
Pro HUD (search and use menus with keyboard)
One of the best and underappreciated features ever, HUD allows you to search and activate menus based on their name and what they do, instead of having to navigate them.
Pro Easy access launcher
That is always accessible on the left side.
Pro Vertical panels work well with multiple monitors
Pro Excellent touch screen compatibility
Unity provides a unified interface for mobile devices and pc.