alt Hacker NewsI think of focus-follows-mouse as a different thing. FFM raises the window under the mouse, but doesn’t move the text insertion point (at least on X and Windows, the only two places I can remember using it). But the Apollo’s window manager was different - moving the mouse moved the insertion point along with it.
but raising the window under the mouse also, for "true" FFM, gives kbd focus to the raised window, which will in turn (via whatever GUI toolkit is being used) moved kbd focus to some widget in the window, if possible.
It is impossible to generalize about this under X Window, since the behavior is entirely controlled by the window manager, and their behavior (a) varies (b) is very customizable.