Navigation acceleration results from lookahead (instead of waiting for user action) and the fact that style and content are merged at the client, removing most style/formatting information from the network.  The presentation of navigation information with a clear spatial metaphor and a view that changes only incrementally also contributes to ease-of-use by making it impossible to become lost. 

FliteMap uses a simple dialect of industry-standard XML delivered over industry-standard HTTP to stream information from the server to the client.