Information sharing apparatus and information sharing system

A novel information sharing apparatus (100) that comprises an information sharing system, connects multiple sites via a network (300) shares each other's handwriting and screens, and eases handvariting sender's psychological burden. In the information sharing system, a handwriting sender generates stroke after a user inputs coordinates, display the stroke in unsteady state, and sends coordinate information to a handwriting receiver. The handwriting receiver generates stroke based on the coordinate information sent from the handwriting sender, displays the stroke, and returns response information for displaying succeeded to the handwriting sender. After receiving the response information from the handwriting receiver, the handwriting sender changes the displayed stroke from unsteady state to steady state.