The emerging technologies of digital video and high-speed networks are combined together in a set-top box to provide a wide variety of value-added services to consumers. The control software in set-top boxes includes a real-time multi-tasking operating system with extensive multimedia support. Along with digital TV functionality, the control software provides an easy to use functional interface for set-top capabilities, such as MPEG decoding, high-speed broadband network interface, 2-way communications and graphics. An application-level software called the navigator performs basic TV functions and has the ability to download and execute interactive multimedia applications from network servers.