Method and system of collaborative browsing

A dynamic collaborative-browsing system enables client programs connected to a computer network to join and leave groups or sessions, to collaboratively browse together as a session, to communicate with other client programs in the session. Each client program in the session may act as a session leader, or may just follow a session leader as it browses network sites of the computer network. The system includes client programs, typically executing on client computers and server software, typically executing on one or more main servers. Network servers, such as Web servers, host a number of network sites each having a location or uniform resource locator (URL). The main server groups into server-defined cells. One or more client programs interact with the server software to cause the server to create a session, to cause the client program to connect to a network site, to notify the server software of the network site's location or URL, and to notify other client programs in the session of the network site's location or URL so that other client programs in the session become connected to the same network site. The server software facilitates the formation of client programs into sessions and allows the client programs to communicate, to connect to and view a same network site, and to perform other collaborative activities. The server software also groups sessions currently connected to network sites in a same cell, and notifies each session and the client programs of the sessions of all of the other sessions and client programs in the same cell. The server software also facilitates communication between the sessions and client programs connected to network sites in the same cell.