Abstract: Methods, apparatus, systems and computer program product for updating a user session in a terminal server environment. Transfer of display data corresponding to an updated user interface can occur via a memory shared between an agent server and an agent client in a terminal server environment. Access to the shared memory can be synchronized via token passing or other operation to prevent simultaneous access to the shared memory. Token sharing and synchronized input/output can be performed using FIFOs, sockets, files, semaphores and the like, allowing communications between the agent server and agent client communications to adapt to different operating system architecture.