Application sharing enables users to share a program running on one computer with other people in a group work such as desktop conferencing. In this paper we propose an application sharing method using window capturing to share applications under MS-Windows with Win 3.1/95/NT and X window system and evaluate the performance of the prototype system. To overcome the system performance degradation as a function of the number of participants, we propose an efficient retransmission strategy to minimize end-to-end delay. With the use of the window capturing method. the prototype system allows any MS-Windows application to be shared regardless of not only the window systems but also the version-up of window systems. (C) 1998 Elsevier Science Ltd. All rights reserved.