There is one big omission in this article, which seems to focus mainly on hydrodynamic computing: "static" hydraulic computing, as implemented with relay valves --- and found major application as the control unit of passenger car automatic trnsmissions throughout much of the last century, before electronic controls became common. Examples:
http://cogpro.com/chapters/M-ThreeSpeedHydramatic/images/M%2...
http://oldcarblog.com/manuals/1970/1970%20Service%20Manual/1...