HTMLCOIN is a Proof-of-Stake (PoS) blockchain platform focused on enabling the practical applications of smart contracts. The HTML blokchain is a hybrid of Ethereum and Bitcoin, and also combines elements of other blockchain infrastructures.

Crown is a cryptocurrency and development platform with a Proof-of-Work (PoW) consensus mechanism, and an emphasis on community governance. It combines some of the technical capabilities of Bitcoin and Dash. It is currently merge mined with Bitcoin, but is developing a new consensus model called Crown Atomic.

Bitcoin Interest is a fork of the Bitcoin protocol that pays coin holders interest. Bitcoin Interest (BCI) allows users to securely earn interest payments without ever moving coins from their wallets. Bitcoin Interest's developers believe that paying interest, weekly or monthly, on inactive crypto-funds can benefit the entire cryptocurrency market by reducing volatility.
Bitcoin Interest (BCI) is the first cryptocurrency protocol to use the ProgPoW consensus algorithm. ProgPoW is a Proof-of-Work algorithm designed to reduce the centralizing tendencies of ASIC mining by making it easier for standard GPU devices to participate in the mining process.