Beam is developing a confidential cryptocurrency that uses the Mimblewimble protocol. It will have a Proof-of-Work (PoW) consensus mechanism, and will enable private transactions that can be audited for compliance purposes.

Stealth is a cryptocurrency focused on privacy and and speed. The Stealth blockchain has a Quantum Proof-of-Stake (qPoS) consensus mechanism that is designed to enable almost instant transactions with improved privacy. Validators on the network are assigned a short quantum of time to validate transactions. The protocol combines two types of blockchain ledgers, for different types of transactions, to improve validation speeds on their platform. The network is powered by the XST coin.

ZCash is a privacy focused cryptocurrency protocol that enables users to make transactions anonymously. Users to hide the sender, receiver, and amount of every transaction. ZCash has several high profile advisers and investors, including: Roger Ver, Gavin Andresen, and Vitalik Buterin.
ZCash has a fixed supply of 21 million coins; 20% of which will be allocated as a founders reward that is split between investors and developers. This founders reward has been the subject of controversy and has led to a fork of the ZCash protocol.