Abstract: A method for operating a mobile computing device includes running a platform-independent application program using a virtual machine operating on the mobile computing device. A server program runs on the mobile computing device so as to access a native function of the mobile computing device that is not supported by the virtual machine. The native function is invoked from the application program by opening a communication connection to the server program using a communication application programming interface (API) of the virtual machine, and sending a message to the server program via the communication connection, so as to cause the server program to access the native function.

Abstract: A method for displaying a map on a mobile client device. The method includes storing map data on a server, the map data including road data with respect to roads of multiple different road types. The server determines a route from a starting point to a destination within an area covered by the map data, the route including one or more route segments. The server defines a corridor map including the route segments and the roads of the different road types that are within different, respective distances, determined by the road types, of the route segments. The server downloads the road data with respect to the route segments and the roads of the different road types included in the corridor map to the client device. The client device, using the downloaded road data, renders one or more images, each image comprising at least a respective portion of the corridor map.

Abstract: A method for displaying a map on a mobile client device. The method includes storing map data on a server, the map data including road data with respect to roads of multiple different road types. The server determines a route from a starting point to a destination within an area covered by the map data, the route including one or more route segments. The server defines a corridor map including the route segments and the roads of the different road types that are within different, respective distances, determined by the road types, of the route segments. The server downloads the road data with respect to the route segments and the roads of the different road types included in the corridor map to the client device. The client device, using the downloaded road data, renders one or more images, each image comprising at least a respective portion of the corridor map.

Abstract: A method for operating a mobile computing device includes running a platform-independent application program using a virtual machine operating on the mobile computing device. A server program runs on the mobile computing device so as to access a native function of the mobile computing device that is not supported by the virtual machine. The native function is invoked from the application program by opening a communication connection to the server program using a communication application programming interface (API) of the virtual machine, and sending a message to the server program via the communication connection, so as to cause the server program to access the native function.