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.

The Ampleforth token is a cryptocurrency with a variable supply. The total number of Ampleforth tokens in circulation changes daily and is adjusted according to the overall demand. The Ampleforth protocol is non-dilutive and ensures that the adjustments in supply that result in response to changes in demand occur proportionally across all the wallets in the network. This ensures that the percentage of each token holders overall ownership of the network remains stable, despite the adjustments in the overall token supply. The protocol is designed to reduce the correlation of the price of Ampleforth to the price of Bitcoin.

QChi is an Ethereum-based token with no clear benefits. Their marketing materials do not provide any specific information about their roadmap or what advantages it offers compared to other cryptocurrencies.