The answer @jstnryan gives is fairly complete. I'd only add that cruzbit exists because for a long time I thought about what an even more simple and easy to use (and more modern!) bitcoin would look like. For example, I don't think the UTXO design is necessary and it adds more complexity than value. Similarly, given the vast majority of transactions are simple standard scripts which effectively transfer value from one public key to another, the scripting system seemed a bit silly. So I got rid of both of those things. And like has been said, I made all protocol messages and primitives JSON for ease of use. I'm not trying to innovate with flashy new bells and whistles. It's an attempt to refine an already amazing idea. I don't know if I succeeded in the eyes of others but I'm happy with the result. Thanks for even taking the time to read about cruzbit!