ST-TCP (Server fault-Tolerant TCP) is an extension of TCP to tolerate TCP server failures. Server fault tolerance is provided by using an active-backup server that keeps track of the state of a TCP connection. The backup server takes over the TCP connection if the primary server fails. This take-over is fast, seamless, and completely transparent to the client. This paper provides a system demonstration of a new ST-TCP prototype. The new prototype incorporates a performance-enhanced architecture and addresses application failure scenarios. Five experiments using this prototype are proposed to demonstrate the following useful features: (1) Client-transparent, seamless failover; (2) Insignificant performance overhead of ST-TCP during failure-free periods; and (3) An ability to tolerate all single crash failures at the hardware and operating system levels, and, most crash failures at the application level.