Bitcoin 2 is a scalable Bitcoin fork that supports private transactions through the Zerocoin protocol and nearly instantly verified payments by Masternodes. Bitcoin 2 uses a Proof of Stake system that allows anyone even running a basic laptop to get block rewards while contributing to running the blockchain.
The main goal of Callisto is to research and develop a reference implementation of a self-sustaining, self-governed, self-funded blockchain ecosystem and development environment. Callisto aims to establish a secure and contribution-friendly environment for further protocol development and improvements. It will rely on a built-in system of smart-contracts to achieve this goal.