Novacoin is a hybrid Proof of work (POW) / Proof of stake (POS) decentralized peer-to-peer cryptocurrency.The Proof of Work part of Novacoin is based on the Scrypt hashing algorithm. Proof of Stake contributes to the coins energy efficiency, as there is no need for nodes to contribute mining power to part of the money creation process. As of now, Novacoin is set to be capped at 2 billion coins. However Novacoin stated that the cap limit may be lifted if the situation requires it. It looks very much like a variation of Sunny King Peercoin.
MX is the proof of rights and interests of MXC trading platform itself. Its total circulation is 3 billion constantly and never be added. MX holders can enjoy a series of rights and interests including asset appreciation, rebates on platform revenue, supervision, voting, etc. MX can be obtained in two ways: mining and buying.