I feel stupid for sticking this talk everywhere I go, but here is it again: https://invidio.us/watch?v=RIctzAQOe44

The crux of it related to the context of this conversation : there ARE pipes in today's GUI: "pipes" (not as in pipe(2) syscall though) for putting the pixels onto the big frame of our screens, with internal (internal piping of X11) / extrenal (netowrk X11 export) protocols that handle the piping.

Rio is beautiful as it can invoke itself in a window of itself (a second nested instance of itself).

Wayland is moving slightly more toward that direction. Looks like the maintainers are sick of some of the terrible designs (yet could do a lot with them) that goes with the X11 protocol and implementation. A wayland windows is more or less just exposing a rectangle for the client to draw in rather than handling a collections of sub windows that compose buttons and GUIs. Toolkits take this role instead.

I know the thread are "GUI pipes" and not "pipes making the GUI"...