PIVX is a cryptocurrency that is focused on privacy, speed, and low transaction fees. It was originally called Darknet and was forked from DASH. PIVX has a strong focus on community governance.
PIVX (Private Instant Verified Transaction) uses a privacy-centric Proof-of-Stake consensus protocol that allows anonymous staking.

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.

Bitcoin Private is a community-driven fork of the Bitcoin protocol. It is somewhat unique in that it was created as a result of a privacy-focused co-fork of Bitcoin and ZClassic. Coins were distributed on a 1:1 basis to BTC and ZCL holders. Bitcoin Private (BTCP) uses the same privacy technology as ZClassic (zk-snarks). Transactions are published on a public blockchain, but the sender, recipient and other transactional metadata remain anonymous. Bitcoin Private has a larger block size, and enables anonymous transactions that are more secure than the original Bitcoin protocol.