Wrapped Bitcoin Tokens (WBTC) is an ERC20 token fully backed by real BTC. The proof of reserves is on-chain, showing the exact 1:1 ratio between minted WBTC tokens and BTC stored by the custodians. A collaborative effort with a community of partners to bring Bitcoin to the Ethereum network will bring the stability and value of Bitcoin to Ethereum's expansive ecosystem of decentralized applications.
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.