We host both for our users, and use Riak for our own datastore. They're both awesome, but quite different. Here's a pretty thourough comparison: https://wiki.b

We host both for our users, and use Riak for our own datastore. They're both awesome, but quite different. Here's a pretty thourough comparison: https://wiki.basho.com/display/RIAK/Riak+Compared+to+MongoDB https://wiki.basho.com/display/RIAK/Riak+Compared+to+MongoDB Note: written by the authors of Riak, but MongoDB contributors chimed in on the comments.