This presentation introduces OpenStreetMap and explains to the audience what sort of rich data set it has. I will also cover different APIs for using the map tiles as well as other APIs that form sister-projects to OSM, such as Nominatim (search), routing, and obtaining current-location information. Some hints on storage and searching will also be given. During the course of the presentation I will also have to dip into some of the theoretical issues surrounding map making in general. Slides: http://derickrethans.nl/talks/osm-london13