METHOD FOR SHARING ANNOTATION INFORMATION TO BE ADDED TO DIGITAL CONTENT, PROGRAM AND COMPUTER SYSTEM

PROBLEM TO BE SOLVED: To provide a mechanism for sharing information (annotation information) added to the digital content such as a Web page between a plurality of users. SOLUTION: An intermediary server is arranged between a client terminal of the users and a server (a Web server) for controlling the digital content. The user desiring to add the common annotation information acquires the original digital content via the intermediary server not from the Web server. In that case, the intermediary server cashes the digital content, and sends it to the client side together with an annotation tool being a program for adding the annotation information. The annotation information made by this annotation tool is held by the intermediary server together with position information for displaying the information. A session key is formed as key information for relating the original digital content to data on the annotation information. The intermediary server forms content reproducing address information URL including data on this session key.