Meanwhile, on a 1980s IBM XT…

Os8088: A powerful Mac-like OS for the IBM XT, 286, 386 os8088.com

Os8088 is a graphical, Mac-like operating system written to run on IBM XT-class machines — hardware with an 8088 processor and no business supporting windows, menus or a mouse pointer. It boots on a 286 and 386 too.