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.

ZCoin is a privacy focused cryptocurrency built on Ethereum. The ZCoin protocol enables anonymous transactions with cryptography that utilizes Zero-Knowledge Proofs (ZKP). ZCoin increases privacy on their network by using a coin-mixer contract that wraps transactions in a serial number and destroying wrapped coins once they have been redeemed.
Zcoin was the first cryptocurrency to use a Merkle Tree Proof (MTP) as its proof of work algorithm. Merkle Tree Proofs are an innovative solution to achieving network consensus, and can increase transaction time while reducing the centralizing tendency of ASIC mining.

FREE Coin is an Ethereum-based token with a focus on being inclusive and encouraging cryptocurrency adoption. Their goal is for the token's price to increase in value, until its price is close to the USD. FREE Coin's site does not provide any details about their development plan or what specific advantages their network will provide.