Client program, terminal, method, server system and server program

The invention provides a client program, terminal, method, server system and server program. A computer-implemented client program that is downloaded and executed by computer terminals to synchronize display screen images of web browsers in the terminals. The client program causes the terminals to function as: an event transmitting unit that transmits an event to a server apparatus, where the event has occurred on a first terminal; an event receiving unit that receives a different event through the server apparatus, where the event has occurred on a different terminal; and a screen-image updating unit that updates a display screen image shown on the first terminal to a screen image in accordance with the different event received through the server apparatus. A computer terminal, computer-implemented method, computer-implemented server system and computer-implemented server program is provided for executing the computer-implemented client program.