What is the main goal of Callisto? Who can explain in more detail?
It's very simple)))
Callisto Network is a blockchain platform with its own cryptocurrency (CLO) that is based on Ethereum protocol, so any Callisto improvements can be applied to Ethereum Classic.
Callisto is NOT a testnet or a hardfork of Ethereum Classic. Callisto Network is developed by Ethereum Commonwealth, one of three ETC development teams.