CBOR is MessagePack. At least cbor-ruby started with the MessagePack sources. The story is that Carsten took MessagePack, wrote a standard and added some things he wanted, and called it something else.
I wrote [1] a pretty comprehensive (and admittedly biased) critique of the CBOR standard years ago.
I wrote [1] a pretty comprehensive (and admittedly biased) critique of the CBOR standard years ago.
[1] https://news.ycombinator.com/item?id=14072598
Disclaimer: I wrote and maintain a MessagePack implementation.