I am new to episerver but do understand cms.
I know that episerver supports google maps.
Is there a way to make episerver support openstreetmap?
What interfaces need to be implemented -- if any?
Anything that you can implement using MVC or Webforms is supported in EPiServer. OpenStreetMap is well documeted so it should be pretty straight forward.
Here is an example using MVC:http://demos.telerik.com/aspnet-mvc/map/index