Quote:In my view of GUI pipes, the only thing in the window drawn by the application is the window content, the rest of the interface is drawn by the window manager or some other program.

This would turn window managers into a huge bloated nightmare.

They would need to implement buttons, menu, popups, text areas, checkboxes, ... Effectively turning them into an API rather than a mere "pipe". This would also be extremely restrictive for softwares likes the Gimp that uses palettes, brushes and so on. It means that the Gimp could not run under all window managers, because not all of them would implement the required buttons drawing.

Pipes are a good mechanism, but they should not be forced in at all costs. Using the pipe(2) syscall internally is sexy though, and I would love to be able to call in any image viewer from within the Gimp to import an image, rather than relying on the builtin GTK file explorer.

As for surf(1), it doesn't use pipes to set the URL, but change a specific X atom on the surf window to define the URL (just like dwm statusbar), which means that xprop is enough to change surf current URL (so X atoms are used as a piping mechanism here, which is great !).