Gateway enabling data communication between devices each having different middleware, home network system thereby, and gateway relaying method

A gateway, which enables data communication between devices having different middlewares in a home network, a home network system, and a data relay method are provided. The gateway includes a generic middleware agent for including various middleware used by devices in the network and formatting a message using one of the middlewares corresponding to the middlewares of the message destination device, and a network access unit for receiving the formatted message from the generic middleware agent and sending the message to the destination device through the network. When devices using different middlewares in the home network system exchange messages, the gateway enables them to communicate effectively, eliminating the need for installation of different middlewares in each of the devices.