Comment by bitwize

XQuartz used to support rooted mode. I played with an early version back in the PowerPC era, and ran a regular desktop with WindowMaker and everything, using software from MacPorts. It was kind of a "parallel universe", as XQuartz would take over the whole screen in rooted mode and you had to switch between it and the Mac desktop, but it looked and functioned like a typical Linux or Unix desktop of the early 2000s.