ŷosokumo was a data mining web service which allowed users to make predictions about new individuals based on data supplied about previously seen examples of similar individuals. It offered quite sophisticated prediction modeling of various kinds. Unfortunately, ŷosokumo no longer exists. However, its protocol specification is an excellent example of a RESTful interface.
The person behind ŷosokumo is Tim Boudreau. He conceived the idea, wrote all the specifications, and implemented all the server code. The Java and C++ API interfaces were developed by Roger House.
Click here to see the complete specification of the ŷosokumo service.
GitHub repository for the Java source code
Javadoc for the programmer using the API
GitHub repository for the C++ source code