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.

Apollo is developing an all-in-one cryptocurrency platform, based on the APL coin. Apollo was created as a fork of NXT, and has a very ambitious plan to integrate a variety of services under one platform, with a strong focus on privacy. Apollo's blockchain is called Hermes and has a Proof-of-Stake consensus mechanism. Some of the features that Apollo's marketing materials claim they are working on are: private transactions with IP masking, smart contracts, encrypted messaging, file sharing, a decentralized marketplace, voting system for governance, decentralized data storage, and a wallet with a built in exchange. John McAfee, a notable blockchain enthusiast and antivirus pioneer, joined the project in October 2018.

Primecoin is a cryptocurrency based on finding prime numbers. Identifying prime numbers plays a central role in cryptography. Primecoin's unique Proof-of-Work (PoW) consensus mechanism is able to increase transaction speeds and improve energy efficiency.
The network searches for special prime number chains known as Cunningham chains and bi-twin chains, which are of interest in mathematical research.