Abstract: The object is to provide an application sharing system enabled to use communication paths efficiency by selectively using multicast communication and unicast communication and to be configured of user terminals alone by providing each terminal with a function to manage a conferencing group. Group information managing sections manage conferencing group information in a distributed manner, and the information is exchanged between terminals. Intra-group control sections manage conferencing groups, only one such section operating for one conferencing group. An application program communicates with application programs of other terminals through an API processing section, via a point-to-point communicating section in unicast communication, or via a multicast communicating section in multicast communication. A program start-up section controls the starting and ending of required processings.

Abstract: In an application sharing system wherein terminals having application programs of the same sort are interconnected via communication channels, the application program (AP) of each of the terminals includes a primary processing part (A), a message transfer part (C), a mode registration part (F), and a share-mode transition control part (J) supplied with a share-mode transition request with channel information for setting a share mode and the channel information in the mode registration part and for making the message transfer part communicate with the application program of a sharing partner of the terminals by the use of a specified channel specified by the channel information to perform a matching operation of matching internal states of the primary processing parts of the application programs of the terminal in question and of the sharing partner.

Abstract: In a network comprising a plurality of terminals which share application programs, when an event occurs in an application of a terminal, the application generates a message of a predetermined format in response to the event. The message includes application identifying information, procedure identifying information and parameter information required for executing the procedure. The message is broadcasted from the terminal to all the terminals through the network. The message may be directly transferred from the transmitter to the receiver within the terminal itself. On receipt of the message, each terminal identifies the procedure based on the message, and executes the procedure on the application using the parameter information.