Abstract: 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.