This NodeJS Sample Source Code is athenahealth's More Disruption Please API samples. The libraries are used to help facilitate access to the API. Each package has a naive implementation of using the API, as well as a library and a testing script to use that library.
Just about every provider of a platform in the cloud is moving down the same path; albeit at different rates of speed. First they figure out that developers of third-party applications can drive more usage of their platform, so they publish a private API. However, it’s not too long before they figure out that making that API public winds up driving the most usage of their platform.