OsmSharp, the OpenStreetMap SDK, offers offline vector map rendering and routing on both iOS and Android. This SDK optimizes routing and logistical information and provides simple cross-platform map views and controls. This is an open-source project that is free to use in any application.
Real estate web service Zillow has progressively made a large amount of information available via its API (our API profile). Recently the Zillow API was updated to include access to additional information, including GetRegionPostings and GetUpdatedPropertyDetails API calls.
You'd hardly notice the difference unless you were looking for it. MapQuest's latest API is a reinvention of its MapQuest API to display maps. So, what's new? Following the company's recent pattern, MapQuest Open API is based on OpenStreetMaps, the crowd-sourced map favored by many modern geo-hackers.