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.
DDK is a community platform that aims to create economic opportunities through the development of blockchain solutions. Since 2015, the DDK community claims to have contributed to a number of blockchain platforms.The DDK platform uses the Delegated Proof of Stake (DPoS) mechanism within its core. According to DDK, one of the advantages of a DPoS blockchain is that it depends on community members to participate in the maintenance and security of the platform so that each member’s participation provides benefit for all.