I wanted to experiment with using MapReduce on Riak, and I found the JSCouch examples to be an excellent learning tool for learning how to do MapReduce for CouchDB (using client-side JavaScript only).
http://labs.mudynamics.com/wp-content/uploads/2009/04/icouch.html
So, as a learning exercise, I tried to re-implement the same basic queries, but using Riak. I used the official JavaScript/jQuery client library from the Riak source code (in client_lib/javascript).
This web page assumes that you followed the instructions in the README and are accessing this via http://127.0.0.1:8098/riak/riak-jscouch/index.html
Click on the following links to execute the queries against this local Riak instance. View the results of each action in the Results section below.