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.

SIBCoin is a Proof-of-Work coin that was originally based on the same code as the Dash blockchain. SIBcoin was developed by a team of cryptocurrency enthusiasts in Siberia and it has gained a significant following in Russia.

EveryCoin is a digital currency that powers the Aaron Platform. The Aaron Platform is a blockchain-based financial project that is located in Thailand. They are developing a digital payment platform that will consist of an exchange, wallet, and a stablecoin called Tabipay that will complement the functions of EveryCoin.