We have a basic http API in beta that lets you read and write map data. This enables some very cool stuff, such as dynamic and programmatically generated maps. Because the API still in beta, we can't promise any support beyond very basic documentation . The API is subject to change, but we'll do our best to warn people before breaking things via the developers update list.
If you are interested in subscribing to our developer updates, please feel free to fill out this Google form. You can also review our current API documentation.