Cloakcoin is a completely secure, fully private and untraceable digital cash with full fungibilty (all coins equivalent). Cloakcoin is able to achieve this privacy through the use of an offchain coin mixing system called “Enigma”. Check out CoinBureau for the complete review on Cloakcoin.
Shardus is building distributed ledger software to remedy the problems of traditional blockchains -- scalability, decentralization and efficiency. The technology being developed will use compute and state sharding to accommodate billions of daily active users, allowing for global-scale decentralized networks.