A server unit which creates drawing data according to an application program corresponding to an input event from a client unit via a network and transmits the drawing data to the client unit to cause the client unit to display the data in a server-based computing system, the server unit comprising: a first drawing instruction transmission module (S1, S3, S5, S6) for transmitting a drawing instruction for the drawing data in real time to the client unit in the order in which the drawing data was created; and a second drawing instruction transmission module (S1, S2, S4, S6) for setting a drawing update interval and for transmitting a drawing instruction for the created drawing data to the client unit in accordance with the set update interval, characterized by a transmission delay measuring module (14b, S1) which measures a transmission delay time in the network; wherein the first drawing instruction transmission module (S1, S3, S5, S6) is adapted for transmitting the drawing instruction to the client unit, when the transmission delay time in the network measured by the transmission delay measuring module is small, and the second drawing instruction transmission module (S1, S2, S4, S6) is adapted for transmitting the drawing instruction to the client unit, when the transmission delay time in the network measured by the transmission delay measuring module is large; and wherein the second drawing instruction transmission module (S1, S2, S4, S6) is adapted for detecting an input event from the client unit and for setting, when an input event has been detected, the drawing update interval such that the drawing update interval is short compared to a default value immediately after the detected input event and for gradually increasing the drawing update interval thereafter until it is returned to said default value, and wherein the second drawing instruction transmission module (S1, S2, S4, S6) is further adapted for transmitting the drawing instruction in the order of a transmission priority of the drawing instruction. a first drawing instruction transmission module (S1, S3, S5, S6) for transmitting a drawing instruction for the drawing data in real time to the client unit in the order in which the drawing data was created; and a second drawing instruction transmission module (S1, S2, S4, S6) for setting a drawing update interval and for transmitting a drawing instruction for the created drawing data to the client unit in accordance with the set update interval, characterized by a transmission delay measuring module (14b, S1) which measures a transmission delay time in the network; wherein the first drawing instruction transmission module (S1, S3, S5, S6) is adapted for transmitting the drawing instruction to the client unit, when the transmission delay time in the network measured by the transmission delay measuring module is small, and the second drawing instruction transmission module (S1, S2, S4, S6) is adapted for transmitting the drawing instruction to the client unit, when the transmission delay time in the network measured by the transmission delay measuring module is large; and wherein the second drawing instruction transmission module (S1, S2, S4, S6) is adapted for detecting an input event from the client unit and for setting, when an input event has been detected, the drawing update interval such that the drawing update interval is short compared to a default value immediately after the detected input event and for gradually increasing the drawing update interval thereafter until it is returned to said default value, and wherein the second drawing instruction transmission module (S1, S2, S4, S6) is further adapted for transmitting the drawing instruction in the order of a transmission priority of the drawing instruction.