No, it’s not a typo. Erjang is a port of Erlang on the JVM
 created by Kresten Krab Thorup. Now his trying to run Riak on top of it:
I’ve spent some time trying to get Riak up and running on Erjang, and here’s a note on current status. We’re very early, but it is basically “up and humping”.
One remark though, Erlang doesn’t feel like a platform that needs the JVM. But still cool!