Google Maps is far ahead of any other map service offered on the Internet, but Microsoft has been working away in the background.
Run in much the same way as Wikipedia, OpenStreetMap is a free open mapping service built on mapping information provided by volunteers. The information is then open to be used by people, companies and other sites.
A number of companies have recently started to move away from Google Maps, as reported by The New York Times. Due to the high fee charged for the Google service, many of these companies have begun to get their data from OpenStreetMap instead. Foursquare, the mobile social media service, has switched - and Apple's iOS management app, iPhoto, has also turned to the Google service.
Microsoft has been giving large amounts of support, as well as large amounts of cash, to the service. Steve Coast, the OpenStreetMap founder, also works for Bing as Principle Architect for Bing Mobile. Microsoft said back in November 2010 that Coast will "develop better mapping experiences for our customers and partners, and lead efforts to engage with OpenStreetMap and other open source and open data projects."