Moonlight is a project still in its early stages and likely will fade away like the many other third-party desktop environments with limited manpower and scope. Moonlight Desktop is trying to be a lightweight desktop for the Raspberry Pi and other low-powered, low-end, old devices -- similar in scope to Xfce, LXDE, Enlightenment, etc. They really don't seem to be far along at all right now and are still working towards an appearance for their desktop.
The described mission is "to create a desktop environment compatible with low performance devices, for the purposes of applications, data and hardware management, built on the principles of modularity, integration, weightlessness and simplicity, utilizing open source technologies. The integration in Moonlight-desktop is at achieved, internally, by grouping the different modules into a single application as plug-ins and, externally, by making an extensive usage of the XDG standards in order to ease the interoperability with third party applications."
Should anyone be interested in learning more about the Moonlight Desktop Environment, visit its GitHub project site.