A hydrodynamic torque converter has a rotary housing which carries a pump assembly and can be driven by the output element of a prime mover in the power train of a motor vehicle, a turbine which is rotatable in the housing and has a hub mounted on the input shaft of a change-speed transmission, and a lockup clutch which, when engaged, can transmit torque from the housing directly to the turbine. One exemplary embodiment positions a substrate in an open air environment. The server is operable to receive the content, detect the modification in the content and form an update message for transmission to each client participating in the instant messaging session.