In some configurations, the Xserver may not be set to start with the system, which means that every time you boot the computer, you will have to manually start the Xserver interface. 1.
But the graphical user interfaces across OSes and even between individual window managers for XServer and Weyland on Linux and BSD are very different and very complicated. Most cross-platform GUI ...
For Ubuntu, the package is xserver-xephyr. For some reason, running it on the Pi just caused the program to stall and do nothing — at least on my setup. However, in theory, you should be able to ...