At first I wanted to make an in-memory database. But I disliked libevent, libev and everything else I saw when I started it. Perhaps I would be more or less happy with libuv, but I was not aware of it back then. By the way redis also provides its own event handling machinery. I guess Salvatore did not like libevent too. But redis is single-threaded while my idea was to heavily rely on multi-threading and fibers (M:N threading model). Quite unexpectedly inventing a multi-threaded event handling framework with an added complexity of fibers took enormous time from me. Anyway now I have a cool framework for multi-threaded servers.
As for in-memory database functionality it only provides memcached compatible interface. As I'm done with the server framework stuff so I am going to add more features. Like persistance, basic redis protocol support, etc.