On Linux, this is a simple addition to your ~/.Xmodmap: keycode 66 = Mode_switch keysym h = h H Left keysym j = j J Down keysym k = k K Up

On Linux, this is a simple addition to your ~/.Xmodmap: keycode 66 = Mode_switch keysym h = h H Left keysym j = j J Down keysym k = k K Up keysym l = l L Right keysym space = space space Return keysym y = y Y BackSpace keysym u = u U Next keysym i = i I Prior keysym o = o O Delete