The Maps API contains a core set of widgets, markers, overlays and web services to enable you to interact with the map in every way. At this point users can add event listeners, map controls and widgets and start interacting with the map.
Yahoo! Maps for ActionScript 3.0 Released
Yahoo released a new Yahoo! Maps API which is entirely built in ActionScript 3.0. This API now integrates a complex set of services and controls that you can leverage in your applications to create custom components, overlays and markers while consuming different webservices provided by Yahoo!, or your own.