I wonder if this system got any inspiration from Plan 9? It looks really similar to 8½, Rob Pike's early window manager for Plan 9 [1]. Or even the Blit [2].

I would love to try out MGR on the Linux framebuffer, though.

Edit: found an interesting 2016 HN thread on "oldschool" windowing systems that also mentions both MGR and 8½ [3].

1: http://doc.cat-v.org/plan_9/4th_edition/papers/812/8%C2%BD.f...

2: https://en.wikipedia.org/wiki/Blit_(computer_terminal)#Windo...

3: https://news.ycombinator.com/item?id=11477565