The present invention is directed to a novel system and method for sharing common data and state information between network connected application clients participating in an application session. The application session is invoked by a host client. The host client is responsible for selectively admitting other network connected clients into the application session, and is also the application client that is responsible for distributing a common set of application data for storage at each admitted application client. The application data includes a unique identifier, assigned by the host client, for each application client in the application session. In the event that an application client effects a change to the application data, that change is communicated to each of the other application clients in the session. In this way, each client is always operating on a common set of application data. When a new client is admitted into an application session, application data is forwarded to it in a manner so that the new client receives data that is synchronized with the data possessed by every other application client in the session. A method for migrating host client duties to another application client is also disclosed.